I might write a paper on this. Topology rake now locally updates a vector field, which it uses to smooth the input and constrain to mesh (including face set) boundaries. This can make an enormous difference for things like smoothing. Note that this is different from the existing 'curvature rake' mode, which also builds a field and which is fed into the input of this new one. The only oddity is that the field is stored in a CD_PROP_COLOR since we don't have a CD_PROP_FLOAT4, and this shows up in the UI (not sure if I'm messing up the CD_TEMPORARY flags or if the UI doesn't check for them).