Do you mean that GUE divers would not be curious and/or would not accept it and/or understand it? May I ask you how many times you faced this problem, and how many GUE divers you met in your life?
My local area has a very strong GUE presence, all of my buddies are GUE trained, and I did fundies to check it out.
Curious is the last adjective I would use to describe their attitude about non standard configurations.
The main dive boat around here is primarily GUE. They will not leave the bay except for the GUE only charters. To get on their tech boat you must be GUE. So, I would say no, they are not accepting. I would be SHOCKED if they would let you do a sidemount tech dive off their boat.
How many times have I faced this problem? Zero. It is their boat, their rules. Compliance isn’t something I do well so I don’t even try. I would say it is them who has the problem; I fundamentally object to exclusionary policies especially when it comes to groups who want money from me.