I know a man (cis and straight, he never had any doubts about his gender and orientation) that owns several skirts. He often wears them around the house - because it's comfy and stylish, not because of some weird fetish. The skirts were sewn to his measure from a fabric he chose.
He now plans to start wearing them outside the house, i.e in public. Is it a good thing from a feminist point of view in your opinion?
As others have said, there is no “cis”. Using that implies “trans” is real.
I used to be all for it. Now? I would look with extreme mistrust at any man doing it, whether he claimed to be a woman or not, because the odds are he’s doing it for a fetish, not just because it’s comfortable/he likes the look/any other innocuous reason.