That makes sense. With my steppers if they ever stall they usually stall by a lot, so I keep things conservative. It's usually because of junk on the ballscrew, hitting the limit without limit switches, rapids that are too fast, or just cutting too hard (happens on Z all the time while drilling). I sort of assumed that servos would be able to read this error, even if it's like 1/2", and correct for it. Good to know!
John