We're not compelled to 'respect' the pronouns of egregious criminals like him. For others, the general MN guideline is for civility and courtesy so actively using terms a person rejects tends to be disallowed - that works both ways to the limited extent we can refuse 'cis' being applied to us.
True. I firmly reject the term "cis". However, it's not something I personally would report.
I like to see who's using it and why. Sometimes new people join this board, some people are new to this whole topic, some people might think that's what you're 'supposed' to say, some don't want to upset anyone etc. etc. All fine. When it's explained, they get it.
More interesting are those who, when the rejection of "cis" is explained, double down, keep using it, tell us it's 'what us lot are', tell us it's 'just a word', basically say we have to accept it.
It tells me a lot about a person.