My key question her is WHY would we do this? Is there some problem with current group sizes? In order for a proposition to be taken seriously, argue why it is needed in the first place.
OP’s just asking about changing group sizes. The replies are hilarious. It’s a big ‘why get good when I can just ask to change the game to suit me’.
When I’m solo - stop all healing
When I’m with 4 - cap size at 4 and stop outside group healing
When I’m with 12 - cap size at 12
When I’m with 36 - cap size at 36
Sounds like a bunch of people who think they’re good, yet have to ask for the game to cater to how they like to play.