I've been working on a Moveo (mostly 3d printed 5dof robotic arm) build for a while. I've been using the teensy 4.1, microros, and teensyduino with pretty good success. My build has 5 steppers, and a servo. Steppers are driven with some TB6560 drivers, and I'm using as5600 magnetic encoders for joint feedback.
The problem I'm running into is that I haven't been able to use the accel stepper class to be able to move all 5 motors at speeds I'd like to, since I've got to do a bunch of other stuff (ie read encoder values, diagnostics, publish feedback, handle subscriptions, etc) on the teensy. To get around this, I'm going to try using pwm as the pulse for the motor drivers, and modify the pwm frequency. According to the teensy documentation, I've only got 7 timers, so I have to use a different timer for each motor. We'll see how it goes though.