Is either the S1 or Odrive Pro suitable for controlling a 24vdc (<15A) brushless (hall sensored) motor using a microcontroller?
Absolutely, that’s the whole point 
you can control over USB, UART, or CAN – the latter two are very easy from most microcontrollers.
Thank you.
Of course! Please let me know how else I can help!
Oh - only thing I’d note is that hall sensors are intrinsically quite low resolution, so low speed velocity and position control may be difficult to achieve. You can use an additional supported encoder to increase the pos/vel control resolution, if needed.
The hall sensors (this is a “sensored” motor) are still good for torque optimization, correct?
Yes, hall sensors will result in full torque at zero speed. Do note though that torque ripple at low speeds will be higher than with an ideal encoder – typically you can expect around 18% torque ripple; this is an intrinsic issue with the low resolution of the hall sensors, but not an issue for many applications. At higher speeds, the ODrive will be able to extrapolate the hall data and provide smoother control.
Once again. Thank you!