diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index e708b1c023ec8b20f512888fe07c5bd3ff77bb8f..7454180f2ae8848c63b8b4dea2cb829da983f2fa 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradlew b/gradlew
index 4f906e0c811fc9e230eb44819f509cd0627f2600..1b6c787337ffb79f0e3cf8b1e9f00f680a959de1 100755
--- a/gradlew
+++ b/gradlew
@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015-2021 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,67 +17,101 @@
 #
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # Attempt to set APP_HOME
+
 # Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
 
 APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
+APP_BASE_NAME=${0##*/}
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
@@ -87,9 +121,9 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
         # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -98,7 +132,7 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
     fi
 else
-    JAVACMD="java"
+    JAVACMD=java
     which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
@@ -106,80 +140,95 @@ location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
 fi
 
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
 # For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
     # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
         fi
-        i=`expr $i + 1`
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
     done
-    case $i in
-        0) set -- ;;
-        1) set -- "$args0" ;;
-        2) set -- "$args0" "$args1" ;;
-        3) set -- "$args0" "$args1" "$args2" ;;
-        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
-    esac
 fi
 
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=`save "$@"`
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
 
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java b/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
index 8f656910ee4d472b69d07e4da54b9b6f382c0b67..9d1ca70acdbe619d773a7a9da11172927ac568ea 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/calc/CalcConfig.java
@@ -224,6 +224,22 @@ public final class CalcConfig {
      */
     public final ValueFormat valueFormat;
 
+    /**
+     * Whether to apply updated distance filter. Note: the
+     * {@code distanceFilterUpdate} flag is registered when a model loads and at
+     * this time cannot be changed with user supplied config.
+     *
+     * <p><b>Default:</b> false
+     */
+    public final boolean distanceFilterUpdate;
+
+    /**
+     * Whether to apply updated grid focal mechanism application.
+     *
+     * <p><b>Default:</b> false
+     */
+    public final boolean gridFocalMechUpdate;
+
     private final Map<Imt, double[]> customImls;
 
     /* Do not serialize to JSON */
@@ -239,6 +255,8 @@ public final class CalcConfig {
       this.vs30s = b.vs30s;
       this.useSiteData = b.useSiteData;
       this.valueFormat = b.valueFormat;
+      this.distanceFilterUpdate = b.distanceFilterUpdate;
+      this.gridFocalMechUpdate = b.gridFocalMechUpdate;
 
       this.customImls = b.customImls;
       this.modelCurves = b.curveMap;
@@ -280,6 +298,8 @@ public final class CalcConfig {
       Set<Double> vs30s;
       Boolean useSiteData;
       ValueFormat valueFormat;
+      Boolean distanceFilterUpdate;
+      Boolean gridFocalMechUpdate;
       Map<Imt, double[]> customImls;
       Map<Imt, XySequence> curveMap;
       Map<Imt, XySequence> logCurveMap;
@@ -294,6 +314,8 @@ public final class CalcConfig {
         checkNotNull(vs30s);
         checkNotNull(useSiteData);
         checkNotNull(valueFormat);
+        checkNotNull(distanceFilterUpdate);
+        checkNotNull(gridFocalMechUpdate);
         checkNotNull(customImls);
         return new Hazard(this);
       }
@@ -307,6 +329,8 @@ public final class CalcConfig {
         this.vs30s = that.vs30s;
         this.useSiteData = that.useSiteData;
         this.valueFormat = that.valueFormat;
+        this.distanceFilterUpdate = that.distanceFilterUpdate;
+        this.gridFocalMechUpdate = that.gridFocalMechUpdate;
         this.customImls = that.customImls;
       }
 
@@ -335,6 +359,12 @@ public final class CalcConfig {
         if (that.valueFormat != null) {
           this.valueFormat = that.valueFormat;
         }
+        if (that.distanceFilterUpdate != null) {
+          this.distanceFilterUpdate = that.distanceFilterUpdate;
+        }
+        if (that.gridFocalMechUpdate != null) {
+          this.gridFocalMechUpdate = that.gridFocalMechUpdate;
+        }
         if (that.customImls != null) {
           this.customImls.putAll(that.customImls);
         }
@@ -841,22 +871,11 @@ public final class CalcConfig {
      */
     public final ThreadCount threadCount;
 
-    /**
-     * Whether to apply updated distance filter.
-     *
-     * <p><b>Default:</b> false
-     */
-    public final boolean distanceFilterUpdate;
-
-    // note: distanceFilterUpdate is picked up when model loads
-    // and cannot be changed with user supplied config
-
     private Performance(Builder b) {
       this.optimizeGrids = b.optimizeGrids;
       this.smoothGrids = b.smoothGrids;
       this.systemPartition = b.systemPartition;
       this.threadCount = b.threadCount;
-      this.distanceFilterUpdate = b.distanceFilterUpdate;
     }
 
     private static final class Builder {
@@ -865,14 +884,12 @@ public final class CalcConfig {
       Boolean smoothGrids;
       Integer systemPartition;
       ThreadCount threadCount;
-      Boolean distanceFilterUpdate;
 
       Performance build() {
         checkNotNull(optimizeGrids);
         checkNotNull(smoothGrids);
         checkNotNull(systemPartition);
         checkNotNull(threadCount);
-        checkNotNull(distanceFilterUpdate);
         return new Performance(this);
       }
 
@@ -881,7 +898,6 @@ public final class CalcConfig {
         this.smoothGrids = that.smoothGrids;
         this.systemPartition = that.systemPartition;
         this.threadCount = that.threadCount;
-        this.distanceFilterUpdate = that.distanceFilterUpdate;
       }
 
       void extend(Builder that) {
@@ -897,9 +913,6 @@ public final class CalcConfig {
         if (that.threadCount != null) {
           this.threadCount = that.threadCount;
         }
-        if (that.distanceFilterUpdate != null) {
-          this.distanceFilterUpdate = that.distanceFilterUpdate;
-        }
       }
     }
   }
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/calc/HazardCalcs.java b/src/main/java/gov/usgs/earthquake/nshmp/calc/HazardCalcs.java
index 37a72c5986e21e507139673ae8886a45792b09bb..ee47a2ceff2386fd00604fc705d8fc7f2c2fbe16 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/calc/HazardCalcs.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/calc/HazardCalcs.java
@@ -146,7 +146,8 @@ public class HazardCalcs {
                     immediateFuture(gss),
                     GridRuptureSet.optimizer(
                         site.location(),
-                        config.performance.smoothGrids)::apply,
+                        config.performance.smoothGrids,
+                        config.hazard.gridFocalMechUpdate)::apply,
                     ex));
                 break;
               }
@@ -214,7 +215,8 @@ public class HazardCalcs {
               if (config.performance.optimizeGrids && gss.optimizable()) {
                 ruptures = GridRuptureSet.optimizer(
                     site.location(),
-                    config.performance.smoothGrids).apply(gss);
+                    config.performance.smoothGrids,
+                    config.hazard.gridFocalMechUpdate).apply(gss);
                 log(log, MSSG_GRID_INIT, ruptures.name(), duration(swSource));
               }
               curveSets.add(sourcesToCurves(ruptures, site, config));
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/model/FaultRuptureSet.java b/src/main/java/gov/usgs/earthquake/nshmp/model/FaultRuptureSet.java
index 9cd7827bcdb0194c1d58ca41be4ecb1ab4cf408c..255d93901ebe514de72d2813e15a26b58a55c69a 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/model/FaultRuptureSet.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/model/FaultRuptureSet.java
@@ -153,7 +153,6 @@ public class FaultRuptureSet extends AbstractRuptureSet<FaultSource> {
   /*
    * Updated distance filter that checks endpoints of trace. If trace is longer
    * than 50 km, intermediate points on trace are also checked.
-   *
    */
   static class DistanceFilterUpdate implements Predicate<FaultSource> {
 
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/model/GridRuptureSet.java b/src/main/java/gov/usgs/earthquake/nshmp/model/GridRuptureSet.java
index 16a2f45a163b0c350125a66edc166d5abffb83a2..c6a718862370778c06f16ca70bb36f6e4a82e672 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/model/GridRuptureSet.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/model/GridRuptureSet.java
@@ -246,7 +246,7 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
   static class Builder extends AbstractRuptureSet.Builder {
 
     private SourceFeature feature; // Grid or Zone
-    private ModelData data;
+    private ModelData data; // unused; clean
 
     private List<Location> locations;
     private List<Mfd> mfds;
@@ -629,8 +629,8 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
    * @param loc reference point for table
    */
   public static Function<GridRuptureSet, RuptureSet<? extends Source>> optimizer(
-      Location loc, boolean smooth) {
-    return new Optimizer(loc, smooth);
+      Location loc, boolean smooth, boolean focalMechUpdate) {
+    return new Optimizer(loc, smooth, focalMechUpdate);
   }
 
   private static class Optimizer implements
@@ -638,15 +638,17 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
 
     private final Location loc;
     private final boolean smooth;
+    private final boolean focalMechUpdate;
 
-    Optimizer(Location loc, boolean smooth) {
+    Optimizer(Location loc, boolean smooth, boolean focalMechUpdate) {
       this.loc = loc;
       this.smooth = smooth;
+      this.focalMechUpdate = focalMechUpdate;
     }
 
     @Override
     public Table apply(GridRuptureSet sources) {
-      return new Table(sources, loc, smooth);
+      return new Table(sources, loc, smooth, focalMechUpdate);
     }
   }
 
@@ -680,6 +682,24 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
    */
   private static final class Table extends AbstractRuptureSet<PointSource> {
 
+    private static final Map<FocalMech, Double> SS_MECH_MAP = new EnumMap<>(FocalMech.class);
+    private static final Map<FocalMech, Double> R_MECH_MAP = new EnumMap<>(FocalMech.class);
+    private static final Map<FocalMech, Double> N_MECH_MAP = new EnumMap<>(FocalMech.class);
+
+    static {
+      SS_MECH_MAP.put(FocalMech.STRIKE_SLIP, 1.0);
+      SS_MECH_MAP.put(FocalMech.REVERSE, 0.0);
+      SS_MECH_MAP.put(FocalMech.NORMAL, 0.0);
+
+      R_MECH_MAP.put(FocalMech.STRIKE_SLIP, 0.0);
+      R_MECH_MAP.put(FocalMech.REVERSE, 1.0);
+      R_MECH_MAP.put(FocalMech.NORMAL, 0.0);
+
+      N_MECH_MAP.put(FocalMech.STRIKE_SLIP, 0.0);
+      N_MECH_MAP.put(FocalMech.REVERSE, 0.0);
+      N_MECH_MAP.put(FocalMech.NORMAL, 1.0);
+    }
+
     private final GridRuptureSet parent;
     private final Location origin;
     private final List<PointSource> sources;
@@ -695,7 +715,11 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
     private int maximumSize;
     private int parentCount;
 
-    private Table(GridRuptureSet parent, Location origin, boolean smoothed) {
+    private Table(
+        GridRuptureSet parent,
+        Location origin,
+        boolean smoothed,
+        boolean focalMechUpdate) {
 
       // This is dirty - arose from conversion to ass constructor taking
       // builder
@@ -713,7 +737,7 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
       this.origin = origin;
       this.sources = parent.singularMechs
           ? initSources(smoothed)
-          : initMultiMechSources(smoothed);
+          : initMultiMechSources(smoothed, focalMechUpdate);
     }
 
     /**
@@ -840,7 +864,9 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
     }
 
     /* always creates finite point sources */
-    private List<PointSource> initMultiMechSources(boolean smoothed) {
+    private List<PointSource> initMultiMechSources(
+        boolean smoothed,
+        boolean focalMechUpdate) {
 
       /* For now, should only be getting here for GR MFDs */
       Mfd modelMfd = parent.mfds.get(0);
@@ -910,6 +936,10 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
       // System.out.println("tableMfd:");
       // System.out.println(tableMfdSum);
 
+      Map<FocalMech, Double> ssMechMap = focalMechUpdate ? SS_MECH_MAP : parent.mechMaps.get(0);
+      Map<FocalMech, Double> rMechMap = focalMechUpdate ? R_MECH_MAP : parent.mechMaps.get(0);
+      Map<FocalMech, Double> nMechMap = focalMechUpdate ? N_MECH_MAP : parent.mechMaps.get(0);
+
       List<Double> distances = ssTable.rows();
       maximumSize = distances.size();
       List<PointSource> b = new ArrayList<>();
@@ -919,12 +949,13 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
 
         Mfd ssMfd = Mfd.create(ssTable.row(r));
         if (ssMfd.data().y(0) > 0.0 || !ssMfd.data().isClear()) {
+
           b.add(new PointSourceFinite(
               parent,
               parent.type(),
               loc,
               ssMfd,
-              parent.mechMaps.get(0),
+              ssMechMap,
               parent.rupScaling,
               parent.depthModel,
               Optional.empty()));
@@ -938,7 +969,7 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
               parent.type(),
               loc,
               rMfd,
-              parent.mechMaps.get(0),
+              rMechMap,
               parent.rupScaling,
               parent.depthModel,
               Optional.empty()));
@@ -952,7 +983,7 @@ public class GridRuptureSet extends AbstractRuptureSet<PointSource> {
               parent.type(),
               loc,
               nMfd,
-              parent.mechMaps.get(0),
+              nMechMap,
               parent.rupScaling,
               parent.depthModel,
               Optional.empty()));
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/model/ModelLoader.java b/src/main/java/gov/usgs/earthquake/nshmp/model/ModelLoader.java
index 3823a2f84e58835df9f86f22decdfbf0cf9aa04b..1a6f9e796dbd9428b9060207983376993f7dab30 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/model/ModelLoader.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/model/ModelLoader.java
@@ -367,7 +367,7 @@ abstract class ModelLoader {
     GmmTree sourceGmms = readGmmTree(dir).or(() -> gmms).orElseThrow();
     SourceConfig srcConfig = readFaultConfig(dir).orElseThrow();
     ModelData data = ModelData.create(setting, sourceGmms, srcConfig);
-    data.useDistanceFilterUpdate(config.performance.distanceFilterUpdate);
+    data.useDistanceFilterUpdate(config.hazard.distanceFilterUpdate);
     return new Fault(dir).loadSourceDirectory(dir, data);
   }
 
@@ -871,7 +871,7 @@ abstract class ModelLoader {
     GmmTree sourceGmms = readGmmTree(dir).or(() -> gmms).orElseThrow();
     SourceConfig srcConfig = readInterfaceConfig(dir).orElseThrow();
     ModelData data = ModelData.create(setting, sourceGmms, srcConfig);
-    data.useDistanceFilterUpdate(config.performance.distanceFilterUpdate);
+    data.useDistanceFilterUpdate(config.hazard.distanceFilterUpdate);
     return new Interface(dir).loadSourceDirectory(dir, data);
   }
 
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/model/PointSourceFinite.java b/src/main/java/gov/usgs/earthquake/nshmp/model/PointSourceFinite.java
index 4608b7ec2cd0fa7a8d2069126a8634dfa71e0f00..3a45f3961b85fa7c7925f74276124ce736fdbda5 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/model/PointSourceFinite.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/model/PointSourceFinite.java
@@ -90,7 +90,7 @@ class PointSourceFinite extends PointSource {
 
   /*
    * NOTE: Although there should not be many instances where a PointSourceFinite
-   * rupture rate is reduced to zero (a mag-depth weight [this is not curently
+   * rupture rate is reduced to zero (a mag-depth weight [this is not currently
    * checked] of an MFD rate could be zero), in the cases where it is, we're
    * doing a little more work than necessary below. We could alternatively
    * short-circuit updateRupture() this method to return null reference but
diff --git a/src/main/resources/calc/calc-config-defaults.json b/src/main/resources/calc/calc-config-defaults.json
index 667030ec7512b78c6daff20bee0ad66404c8d311..f42c84b7133cd3642f94cfa02547c5bf49e7307c 100644
--- a/src/main/resources/calc/calc-config-defaults.json
+++ b/src/main/resources/calc/calc-config-defaults.json
@@ -14,6 +14,8 @@
     "vs30s": [],
     "useSiteData": true,
     "valueFormat": "ANNUAL_RATE",
+    "distanceFilterUpdate": true,
+    "gridFocalMechUpdate": true,
     "customImls": {}
   },
   "gmm": {
@@ -59,7 +61,6 @@
     "optimizeGrids": true,
     "smoothGrids": true,
     "systemPartition": 1000,
-    "threadCount": "ALL",
-    "distanceFilterUpdate": true
+    "threadCount": "ALL"
   }
 }
diff --git a/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java b/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
index 430d303bc70f6289546504b9d192ab6202689f20..91e2f1b3cb942c8e90e8a4aee2ce2edea77a2951 100644
--- a/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
+++ b/src/test/java/gov/usgs/earthquake/nshmp/calc/CalcConfigTests.java
@@ -137,6 +137,8 @@ class CalcConfigTests {
     assertEquals(EnumSet.noneOf(SourceType.class), def.sourceTypes);
     assertEquals(true, def.useSiteData);
     assertEquals(ValueFormat.ANNUAL_RATE, def.valueFormat);
+    assertEquals(true, def.distanceFilterUpdate);
+    assertEquals(true, def.gridFocalMechUpdate);
 
     Map<Imt, XySequence> imlMap = def.modelCurves();
     Map<Imt, XySequence> imlMapExpect = new EnumMap<>(Imt.class);
@@ -258,6 +260,8 @@ class CalcConfigTests {
     assertEquals(Set.of(260.0, 760.0), def.vs30s);
     assertEquals(false, def.useSiteData);
     assertEquals(ValueFormat.POISSON_PROBABILITY, def.valueFormat);
+    assertEquals(false, def.distanceFilterUpdate);
+    assertEquals(false, def.gridFocalMechUpdate);
 
     assertArrayEquals(
         IMLS_PGA_CUSTOM,
@@ -272,6 +276,8 @@ class CalcConfigTests {
     assertEquals(Set.of(), def.vs30s);
     assertEquals(true, def.useSiteData);
     assertEquals(ValueFormat.ANNUAL_RATE, def.valueFormat);
+    assertEquals(true, def.distanceFilterUpdate);
+    assertEquals(true, def.gridFocalMechUpdate);
   }
 
   @Test
@@ -382,21 +388,18 @@ class CalcConfigTests {
     assertEquals(true, def.smoothGrids);
     assertEquals(1000, def.systemPartition);
     assertEquals(ThreadCount.ALL, def.threadCount);
-    assertEquals(true, def.distanceFilterUpdate);
 
     def = EXTENDS.performance;
     assertEquals(false, def.optimizeGrids);
     assertEquals(false, def.smoothGrids);
     assertEquals(500, def.systemPartition);
     assertEquals(ThreadCount.ONE, def.threadCount);
-    assertEquals(false, def.distanceFilterUpdate);
 
     def = EXTENDS_EMPTY.performance;
     assertEquals(true, def.optimizeGrids);
     assertEquals(true, def.smoothGrids);
     assertEquals(1000, def.systemPartition);
     assertEquals(ThreadCount.ALL, def.threadCount);
-    assertEquals(true, def.distanceFilterUpdate);
   }
 
   static double[] imlsForImt(Imt imt) {
diff --git a/src/test/resources/calc/calc-config-extends.json b/src/test/resources/calc/calc-config-extends.json
index 39726d13bd87e17672d9c2c77caee082bbe83eb9..8a16c44ded7298ef56bc79e4d13a4b166fdac5a6 100644
--- a/src/test/resources/calc/calc-config-extends.json
+++ b/src/test/resources/calc/calc-config-extends.json
@@ -10,6 +10,8 @@
     "vs30s": [ 260, 760 ],
     "useSiteData": false,
     "valueFormat": "POISSON_PROBABILITY",
+    "distanceFilterUpdate": false,
+    "gridFocalMechUpdate": false,
     "customImls": {
       "PGA": [0.0025, 0.0075, 0.0169, 0.0380, 0.0854, 0.192, 0.432, 0.973, 2.19, 4.92]
     }
@@ -56,7 +58,6 @@
     "optimizeGrids": false,
     "smoothGrids": false,
     "systemPartition": 500,
-    "threadCount": "ONE",
-    "distanceFilterUpdate": false
+    "threadCount": "ONE"
   }
 }
diff --git a/src/test/resources/model/test-model/calc-config.json b/src/test/resources/model/test-model/calc-config.json
index c86e4964bf0f5c2d9e8108e269da59adc2ac5cad..458a33e71b251f184a56945743651a8cabd5a609 100644
--- a/src/test/resources/model/test-model/calc-config.json
+++ b/src/test/resources/model/test-model/calc-config.json
@@ -8,7 +8,8 @@
       "SA0P2": [0.0025, 0.0045, 0.0075, 0.0113, 0.0169, 0.0253, 0.038, 0.057, 0.0854, 0.128, 0.192, 0.288, 0.432, 0.649, 0.973, 1.46, 2.19, 3.28, 4.92, 7.38],
       "SA1P0": [0.0025, 0.0045, 0.0075, 0.0113, 0.0169, 0.0253, 0.038, 0.057, 0.0854, 0.128, 0.192, 0.288, 0.432, 0.649, 0.973, 1.46, 2.19, 3.28, 4.92, 7.38],
       "SA5P0": [0.0025, 0.0045, 0.0075, 0.0113, 0.0169, 0.0253, 0.038, 0.057, 0.0854, 0.128, 0.192, 0.288, 0.432, 0.649, 0.973, 1.46, 2.19, 3.28, 4.92, 7.38]
-    }
+    },
+    "gridFocalMechUpdate": false
   },
   "output": {
     "directory": "tmp/model-tests"