Comment by mochomocha

Every physical model has its strengths and weaknesses. In this case you're correct that no emphasis has been put on the human-instrument coupling, but they've worked harder than usual on the air/instrument coupling which makes sense givwn their goal of helping violin makers. However there are plenty of research work on physical modeling between human and instrument (Serafin, Woodhouse, Chaigne etc from 1-2 decades ago) esp for violin. For string plucking & striking specifically, the coupling is modeled in a few commercial products (Pianoteq is a popular one) [disclaimer: I used to sell a guitar software doing this as well and met some of these acoustics experts a long time ago - these were fun times going down the rabbit hole of physical modeling]