Vortex Sound Research

Hi all you experts!

I'm designing an open-source musical instrument (https://github.com/ttempe/Pocket_Organ), and expression and low manufacturing cost are two design goals. I'm currently using a SAM2695 single-chip MIDI synth, which is quite OK in terms of sounds, but lacks in expression (I'd love to be able to change the texture of the sound in real-time, channel-by-channel, a bit like on a Sylpyo or Orba).

I wonder if it would be feasible to run a software real-time synth on a 32-bit microcontroller (say an ESP32 or a STM32F4, or the likes), without adding too much PCB footprint, with at least 16 notes polyphony and a sound quality that wouldn't be a put-off to normal consumers.