that's why FluidNC is so great: https://github.com/bdring/FluidNC Designed specifically for teh ESP32, it's a ground-up rewrite of grbl for ESP32. I've replaced all my various firmwares across devices (not my printers- those run prusa firmware) I build or use (microscopes, CNCs, various stages).

I still like the idea of a microcontroller doing the low-level work mostly controlled by a higher level microprocessor/SBC but it seems unnecessary?