How should LGB actually go about dropping the T(Q+)?

Just by cutting ties completely.

I suppose if there were situations in which there's a need for formality, I think it should be stated in a way such a this. "While the LGB community expresses support for all victims of prejudice cruelty, we acknowledge our needs, interests, identities, etc, as separate and hereby distance ourselves and our involvement with others, suitably, and to provide clarity for our intentions and our presence. We define ourselves as individual and act to promote that message."

This would be a very neutral message which underlines and explains the basic point. After that, sure, posts themselves could discuss flaws in "gender theory" and why some might not like it, along with other things, and etc.