So if I understand the trans activist position, you have to use the right pronoun, but nobody could object to the noun ‘TERF’ because it is objectively true
TERF is less straightforward because it's not an immutable characteristic but an ideology & no-one is morally obliged to avoid descriptors which have derogatory connotations for those. I tend to avoid now for reasons of diplomacy & not being mistaken for having a tribal position.