On-hold across the button / margin of error

Merry Christmas everyone! I had a question about the on-hold directive – I have a rather large button and when holding it with my finger, it works if I’m careful to steady my hand so that it doesn’t move at all - however, I’d like to allow for a little bit of movement during the hold so long as the hold is still on the button itself. Any ideas? Is there also a way to change the 500ms time for this? Or is there a custom directive you might suggest to solve both of these issues? Thanks so much!