Bill Zebub
“It’s probably Matt Mercer’s fault.”
I don't. But I can't imagine needing a grid to model such things as hampering an enemy from closing in on you or pushing an enemy away so it doesn't threaten one of your allies anymore.
The way I would do it is to ask the player what they are hoping to achieve by using the ability. Not, "Well I want to push them away" but "I'm trying to give my companion a chance to get away without provoking an opportunity attack."
I can work with that.