good physical modelling isn’t possible with the er301 alone, and synthesizers like prism, kaivo or chromaphone are such complex synths, i don’t think it’s possible to build something like that within modular, especially not polyphonic. the heart of prism is a modal bank, consisting of many many resonant filters which play together nicely to build a sort of body of a sound which you excite. even if you have dozens of resonant bandpass filters you still would need an “intelligent” interface to modulate them all simultaneously.
crude karplus strong or resonant filters however are certainly possible to build, however it’s difficult and not so practical since good physical modelling plays with nonlinearities and feedback paths to achieve a natural sound. i remember however that brian has added a waveguide model onto the “eventually” tab in the o/d wiki page, that definitely would be awesome!!!