Would it be feasible to develop code for driving AC induction motors?
It is feasible, It just need some firmware changes.
VESC already does, in the terminal you can run an open loop 3 phase at a configurable frequency. An ACIM won't freak out with that signal, it will spin.
However, what you and me want is FOC. The FOC control loop for driving an ACIM is different because it introduces the concept of slip. Those are few new lines of of code.
The challenging part is developing a new observer algorithm to keep track of the flux angle. Its easier when you have magnets, the flux rotates with the mechanical angle, but in ACIM the flux is slipping away and you need to estimate its angle, and also depends on rotor inductance and resistance, which have quite some temperature dependency.
So yeah, its doable, I have a board ready to ship to Benjamin if its useful to him for ACIM development.