What typically happens with a VFD when you draw too many amps is that it will fault (shut off) due to Overcurrent Fault. You reset the fault, and the VFD will start right back up again. However, drawing too much current too often is the electrical version of wear and tear. Over time things give up when you beat on them too hard. KBAC drives are great little drives, but industrial they are not. I'd be hesitant to run my KBAC the way we run VFDs in factories. (especially since I'm the one paying for it, and I don't have a parts room with ten more). I'm a big believer in giving things a cushion whenever possible. Granted, running a belt grinder is in no way, shape, or form difficult on a VFD. Running your motor at 120Hz for a long time is about the only thing we do that would be considered abusive. When you are hogging steel (profiling blanks) is when you'll work that motor the hardest. Put your hand over the motor housing once in a while. If you wouldn't touch the motor, it's time to throttle down and let it cool. That motor you posted a picture of has Class F insulation. (class F is typical for a motor). True Inverter Duty motors have Class H or I insulation and will take more of a beating before the insulation breaks down the windings ground out, but in my opinion there's no need to pay for an inverter duty motor to run a belt grinder. If the motor needs a break, your back probably does, too.
Something else to consider: most people set up their VFD to allow 2x motor speed. When the potentiometer on the front is set to 100%, the motor will be running at 120Hz. This is going to draw slightly higher amps than the nameplate. This is not a HP issue, it's a cooling issue. Any 60Hz motor running 120Hz for an extended amount of time is going to overheat.
220VAC isn't that hard to come by. I ran my grinder off a 25ft length of SO cord to my dryer outlet for a year. The wife would come yell at me to quit grinding because she needed to dry clothes sometimes, but we made it work. I was renting at the time, so it was a good workaround. Just something to think about.