That's just more mental gymnastics, in my view.

I'm not really concerned with what extremists and militants "do" or "don't do," in terms of pushing their agendas. If we stop doing things just because anyone with a nefarious agenda could co-opt it, we'll eventually slide down the slippery slope to the point where we're surrendering all of our shared vernacular to them.

Also, a white supremacist is only going to capitalize "White" while juxtaposing that spelling alongside all lowercase spellings for any other racial groups -- or, more likely, using derogatory slurs in place of "Black," "Asian," "Latino(a)(x)", etc.

If one clearly uses White, Black, Asian, Middle Eastern, Desi, North African, Hispanic, Latino, Chicano, Indigenous, etc., all in tandem, juxtaposed alongside of one another, all with their first letters capitalized -- it will be clear that the writer's/speaker's/communicator's motive is symmetry rather than supremacy.