Pretty simple concept. Not sure on how many people would use it but I'm sure it would be useful.
On my community site I like to have different groups for different types of members. So things like Admin, Mod, Banned, Owner, Etc but every now and then I want a member group but called something else... So like 'Community Helper' a simple group to identify that the member is someone you know can speak for the community but doesn't actually have any more power than a member. My suggestion would be to add a way to make a Clone group. A Clone group would be where you can Clone a group but the only things you can do with the groups settings is to edit the very first section, this one to be precise https://i.imgur.com/W6edGDf.png. Then when you change a permission on the Original group then the clone groups would be updated too. So logically you could have a lot of groups but still be able to manage them in a simple and efficient manner.
Just a thought. I would love to see that sort of thing become a thing.