mmm full offence but gay love and gay sex has always been, for lack of a less dramatic word, revolutionary, (this goes for gay sex especially because in the past and even now there’s the whole ‘its okay to have feelings as long as you dont act on them sexually : ))))’) so like erasing a gay character’s canon sexual feelings with ace headcanons is kinda homophobic.
its a bit different erasing romantic feelings because sexual feelings could still remain depending on the headcanon but tbh you shouldnt really erase either because its important representation. ace rep is important but dont always use it on gay characters, you arent slick. there are plenty others to use.