With so many headmaster references (the other school) I wonder if this has the official blessings
With the involvement of the male students, be it for their spanking or them administering the punishment to the girls, I suggest you add a "sissification training punishment" and/or "girl trapped in a guy's body: trans-sexual transformation" type storyline for the guys involved.
I mean, it'll probably be less upsetting for most if the guys were girly subs rather than macho men ¯\_ (ツ)_/¯
I, for one, would be much more willing to spank the guys and/or let them punish the girls if the guy in question was in a chastity cage, wearing a skirt & anal plug, rather than be a masculine guy with a boner ¯\_ (ツ)_/¯
Also, most sissification/transformation games are from the pov of the male sub, with someone always moaning about how the genre lacks games from the pov of a dom male MC. So it might be appreciated.
Anyway, these content would be small & optional, side-quest storylines at most, the main point being to make the guys less male & more girly... pampered rich femboys in comparison to a gritty disciplinarian like MC...
With this, maybe out of the 70-80% who will skip all content involving the male students you can get 10-20% back to not skipping it? Maybe get a poll or something if this is preferable to "real men" male students?
Good Luck with the game
PS:Also, allow to skip animations.
Also, provide a easy/casual mode. It's a lot of work to manually detect everything without any hints & the rollback disabled...