Warp stabilizer ease on and off
Often stabilisation is only needed for part of the footage duration to stabilise the camera. When the subject makes a move the whole shot wobbles. If the 'smooth motion' were animatable you could ease it off to zero when the camera person gets his/her/its sht together, lol. This would be far easier than masking the subject.
Pierre Louis Beranek commented
Yes! 100! Here's a tip that might help you in the meantime: https://www.facebook.com/groups/1638270639681590/search?q=warp. Is this the same way you mask your subject?