Oh man, genderswapped madokas are my jam. I think there's money in such a thing in some form. Perhaps keeping the Madoka figure female while everyone else is male?
At a certain point, it wouldn't even be seen as a rip-off and instead cross into the [drawing inspiration] territory.
The problem with a lot of genderswap art is that girls are present, if the artist just flips everybody or whatnot. Even though most of it isn't couple-y, I'd still worry, even though the ftm is clearly the picture's focus.