I think removing them would be easier.
I take it when two players are IL'd then their stats and rolls etc are sent to the server and info is returned to the client? Aren't the combat rings that show hits and misses tied into all of that? If so wouldn't that tie up more server time if someone else were to be able to see the changes? I'm not too savvy on the actual workings tho' thats just an idea I have on how it works.
Can't they be turned off with the Ctrl+F command?
I think removing them would do well... There's no real need for them, considering that your hotbar will display whether your move has gone through or not with a special. You really don't need a ring to tell you whether you've just hit someone or not. If the game's system requires them, keep 'em, but give em o% opacity..
They were added in for CR2 and since then never really seen the purpose for having them in there. They weren't there for CR1 and since abilities have a hit/miss animation I really see no reason for them, and they get bugged alot.
I think they are there as they show you who has won or lost the normal attack rolls, specials have the green or red flash on the icon on the hotbars.
I would be ok with them getting shot of the green rings but the red flash on the ground at the loser of the current roll's feet should stay as I am using them, unless they add the red/green flash to the normal attack tactic hotbar icons.
EDIT: I hate the bug when they stay behind after interlock has finished.