Seems like you may need to ramp up speed to avoid burning out the controller.
Would it be possible to write a Meta Code macro in RRF to do the ramp-up?
How would you set this up?
define a GPIO pin as 'spindle-output' trigger
the trigger-macro reads the PWM duty cycle (that's the hard part of the equation)
the macro ramps-up the heater output
optionally sets another trigger, when motor is ramped up
