ESP32, TMC2209, and UART Control of Microstepping

Maybe think of it as needing one driver to do the software/UART configuration and a separate second driver to do the STEP/DIR acceleration/targeting/stepping/motion control. It looks like you setup both drivers in #38, but you don't seem to use the fastAccelStepper motion control driver in loop(). I can't test your code since I don't have your hardware setup.

Can you use a plain STEP/DIR FastAccelStepper example like:

...but modified to work with your current hardware and wiring?