Its a good list of HS based games @chocolatedrop.
For 'apocalyptic games' 'Now and Then' and 'The interim Domain' author works on their next game TOXICity of the same theme. Also there is 'Contagion Crisis' with apocalyptic story but quite a rough content.
'Stray incubus' - While great one, note that its most probably abandoned - There are new dev's team now, but I don't hold hopes, they will be able to get even remotely close to Flint(My 2c). If going with abandoned games 'Evermore' and 'Unraveling August' are worth playing.
'Between humanity, Fates collide' - Those two are good - I'll recommend to add 'The New Horizon' to this group as well.
As part of your first list I would also recommend 'Realm Invader'.
For fantasy stories with Elves,etc(Similar to this one): 'Inanna Revenge'.
If NSFW is not a 'must have' and good story is appreciated as well then 'Lycoris Radiata' has very good story(Not finished).
I currently play 'City Devil - Restart'- The start seems promising, but can't yet tell on further episodes.