Interesting thread. Funny in parts. Some good arguments, none of them from OP, who nevertheless has kept on with his cheerful but elsewhere perforce dangerous nonsense.
Sometimes it strikes me too much is given to what we might categorise as the opposition, epitomised here by OP. (Part of being too nice, really.) Here is a suggestion; I have done this recently in real life, with good-enough results. (I used to work in the Argument Clinic, much beloved of Monty Python fans -- paid to teach arguing through argument. This is for free, though.)
Most really stupid arguments start off stupid and never improve. Often the best strategy is to go back to the beginning and attack the roots, so to speak. (This is not a plea for definition of terms or anything like that. Definition is most often a red herring anyway. ...)
The argument about 'trans', most readers here will have noticed, is a really stupid one. OK, how does it start? We trans people (or transpeople, yes some people think the spacing matters) are people whose gender identity ...
-- Wait! 'Gender identity', you say? But there is no such thing as gender identity.
Erh, but if there is no such thing as gender identity, then there is no such thing as a trans person (or transper ..., no, already too tedious).
-- Yes, right. No such thing. Not anywhere. Never was. Could not be.
But, but, ... Erasing identity! Transphobia! Literal violence! Equality Act! Cis! Section 28! LGBTQWERTYUIOP! Hormones in wombs! Monkeys with toys! Misgendering! Pronouns!
-- Sad, is it not? But there you are. And you know what? I do not care. Now piss off and stop bothering me. Oh, and if I catch you around my children again, ... [Redacted for Mumsnet acceptability.]
Just a suggestion. It has the advantage of truth, anyway.