There is a thread, somebody tried to make it work with steppers: https://www.cnczone.com/forums/mecha...-software.html
No conclusion but it might give us ideas....
You should keep on pursuing the DC servo/gearbox approach, the air-cylinder driven solution doesn't go well with using different types of tool holders, which will require complete disengagement from the drawbar. The torque limits (Vref) could be made to change via relays/mosfet-switches driven by the tool-change macro. But it still will require a way to align the drawbar square with the driven socket, some kind of drawbar position sensor or magnetic forced alignment, there is also the drawbar brake which must be handled by the macro too. It will be good to include a selectable impact phase to tighten the nut and release it without over-stressing the motor by stalling it.
That Brushless CAN motor seems interesting too.