I understand why you didn't mention a particular fetish. I just disagree with you, is all
I don't see any logic in opening up an Ex thread so two players can explore fetish X and then two more go in there and get stuck into the rest of the alphabet. That could happen under your thinking and to me is a disaster waiting to happen. By saying "This thread is for scenes including extreme fetish X only" you safeguard against stomping all other everyone's offs all over again.
By all means later on discuss among the group the inclusion of another if everyone is happy with it, or if some are not, set up another separate thread.
Edit -- Haibane, Sasha please remove the discussion about extreme fetishes from here. This is too much of a general thread for such discussion in my opinion.
I think its important that it remains and I wrote it here in the full knowledge that the general public can see it - and wanting
them to see it. By listing them I am not playing out scenes including them and the simple statement of their existence and a description will not offend anyone considering joining this site - who by definition is a mature adult. I think its good that other players and site members can see it too because I think there is some misunderstanding here about what Ex is and what the Ex board is for.
The caveat to that is that this is just my opinion of what is considered Extreme at E, the site owner and admins may disagree but I think the ones I list are pretty much most of them.
EDIT: I have summarized the descriptions more if that helps.