I have many iMessage groups, but it is an almost unspoken rule that you do NOT add a green bubble user to the group. It downgrades to standard MMS which doesn'

I have many iMessage groups, but it is an almost unspoken rule that you do NOT add a green bubble user to the group. It downgrades to standard MMS which doesn't have all of the features, AND delivery is hit or miss. With iMessage I can be fairly sure that all messages will arrive, with MMS groups... it's a shit show. There's been plenty of times where someone whose a green bubble will receive only part of the group messages, or none of them whereas the rest of us do. It all depends on the carrier.