I always modify jumping and high impact moves (I get plenty of impact when I run/jog). I can figure out all the modifications myself but I appreciate when the instructor shows it or has a modifier.
I'm not offended by the word modifier. I don't think it makes what I'm doing any less, just what I feel my body can handle (as I've aged and gained some weight). I still feel it and respect my limits, injuring myself trying to keep up has taught me that the hard way!