With update to nshmp-lib 0.7.2 Models class provides two public methods:
trees(model) returns a summary of all trees in model (this can be used to populate menus)
tree(model, id) returns the details of a single source tree and contains all MFDs
As each model will be running as an instance the relevant HazardModel should be available to pass as an argument to these two methods and the relevant URLs would look like:
.../ws/nshmp/model-id/dynamic/trees
.../ws/nshmp/model-id/dynamic/tree?id=#
A lot can be done to massage the serialized forms being provided right now. For instance we may want to collapse/combine some of the MFDs especially for bushier logic trees.