The most annoying part of "TERF is a slur" is that "TERF" isn't even a particularly rude thing to call them. It's just noting that they are self-described radical feminists who exclude trans women.

If we were going to be real about this they're not radical , they're only feminists insofar that feminism is capable of being reactionary, and they mean to destroy trans people rather than simply excluding us.

My preferred term for people like that is "fucking shithead transphobe". Bit ruder.