If the Genderists like using the term, I try & avoid using it.
I prefer to say something like "non-believer" or "realist".
I also never call them "TRAs" now, only "Genderists" or Gender Extremists, which I feel is a better definition of that they are.
Except TERF, I'll take that & run with the TERFery so it can't be the slur they want it to be.
You are absolutely right OP, that words are important & allowing the terms we use for ourselves be guided by Genderists is putting us at a disadvantage.