The problem with tying performance aspects to velocity is, legato and detached has NOTHING to do with volume. You can play detached quietly, and legato at fff. And vice versa.

And initial velocity has little to do with the END of a note, when you are talking strings, or brasswinds, or anything else other than percussive sounds.

Something they could take a look at for SA3 is tying increasing dynamics performance switches to the footpedal. Acoustic instruments behave VERY differently depending on how loud a phrase you want to play, but some things ARE independent of velocity. A string patch with little no volume response to velocity, but responds to footpedal would be awesome!