Based on my limited experience with RPCs I'll say that it should work fine. I've had no problems starting a 10HP spindle motor on a 15HP RPC. Having said that, the spindle is operated by a VFD so it doesn't start across the line, ramp up is about 1.5-2 seconds or so.
If you have a VFD or other controller on your spindle I would say there is no problem.