Can't he just use a spell to change his gender permanently?
Considering that the bitchy rival's botched potion managed to turn a regular housecat into a sentient Khajit-like creature capable of speaking very eloquently and the only way that they were able to turn him back was a whole different spell, there
absolutely should be a permanent sex change spell or potion or
something. But then they wouldn't have a magical HRT allegory and we can't go without that, now can we?
Also, the show has this concept of "old magic vs. new magic" where old magic (something Sage learned from her mother and practiced before she started attending the academy) is magic in the more traditional sense, with it being difficult to harness with lots of rituals and every spell having a cost (whether that be material components or the caster's energy), as well as having limitations in what it can do. New magic is easy to use and learn, instantaneously castable, can do practically anything, and comes at literally no cost to the caster. The show keeps beating the audience over the head with how new magic is so much better and easier and that traditionalist magic users like Sage's mom being painted as sticks in the mud, backwards, or closed minded for not using it.
I can't tell if this is supposed to be them taking jabs at IRL traditionalists/conservatives, or if they're trying to hint that new magic is
actually evil since it's practically too good to be true. Apparently Sage's mom tried experimenting with new magic in her past, but renounced it and refuses to acknowledge that she practiced it, which could honestly work for either interpretation. The second option would actually kind of impress me if they went that route because they'd at least be doing
something mildly interesting with the writing. And if there's a person of the writing team with even a lick of writing skills (doubtful) they could do something VERY interesting with the fact that new magic is secretly evil and one of the main characters has been ingesting it every month, though the chances of that subplot happening are smaller than a snowy day in hell since it'd imply that the fantasy HRT
might be a bad thing, actually.