I don't like the idea of a quirk-remover myself, especially if the PCs would then inexplicably be shielded from such removal due to plot armor and shit. If they have no more conviction than trying to make humanity as a whole quirkless again, I feel like it'd make most sense to go after the younger generation rather than established badasses, especially if the targets have to be subdued for a long time.

Which is sorta horrible and gross too.