I’m not sure, but I assume the problem here is the “step-like” response you’ll be getting from the sensor in this situation.
With Halls, the angle will only update when the next hall sensor interrupt is received. Until then, the angle will stick at the old value.
So from the point of view of the controller, it will drive the motor, not see any change in angle, increase the voltage, still not see any change, increase the voltage some more, etc… then, finally, when the interrupt arrives, the angle will change by a whole lot all at once, and the controller will go “whoa”, and back down again… and repeat.
I think the sensor value has to change more smoothly to get smooth control of the motor.
I think perhaps the modification @dekutree64 just made (see end of this thread: https://community.simplefoc.com/t/programming-the-lepton-from-start-to-finish/2935/85?u=runger) could be really interesting for you in this situation…