I have to go, so just a quick prototype, for one-way (only grow) - it just happens to give the result you want for the example, but I know if there was a 2-face separation on the ear loop, you would expect the separated part to disappear, and this doesn't do it:
And this goes the other way:
So if you do the first, then the 2nd, you're probably fine, but there's also a question of how many iterations (I did 100) - you need to implement a "while" loop. It can be done, I think I'll start another question for that and link here, but that tomorrow…