Again, and not just Cozumel, if a diver wants to dive GUE/DIR "standards" whatever all that entails, best bring your own kit and your own approved buddies. I am certain that if a large enough group, and large enough depends upon the resort/dive center, they will bend over backwards to accommodate. And even get you all on a boat to yourselves or split up with different DMs. If doing rebreathers or tri-mix then advance arrangements are going to have to happen with a facility that can support that type of diving.
A diver friend who just recently visited Roatan sent some pics to share on his drop box. I am not impressed with what I saw, mostly bluish green covered dead coral stumps and kind of hazy water. Perhaps it was just the photos did not show the coral or whatever or the strobes were not turned on or something. But there is plenty of color in Cozumel, 9/24: