Since we're coming up to the end, I've got a few scene suggestions. Haven't played any updates for a while, because I decided I'm going to replay in full when finished - so if any are already in the game, my bad
Reverse Cumflation - Melissa or Jill taking the potion, and then expanding you instead. Bonus points if the scene prompt is for you to drink it, but then they flip the tables and take it off you
Darkwood - I know this as a representation of an actual person, so there might be some limits on how they wanted to be included? I notice there's nothing with them being on top. Perhaps something, even mutually?
Other futa - any other futa stuff in general if you can squeeze any extra scenes in. There was a period a while ago when you added quite a lot, almost back to back - but a few more would be cool before we finish.
Feet - I don't think feet are your thing (warlock and boobs, not warlock and soles), and only a couple of pictures have any feet in at all - like some of Melissa's, but one of the best things about this game is the variety. A little extra would be nice - and Melissa seems like someone who would have a scene like that too
Bad Ends - I don't actually rememebr the being any, but certan descions or fight losses could lead to COC style bad ends - annoy someone too much, they enslave you, maybe you get pulled back to the demon realm with the succubus. Or even just end up dead - but it's just a bit extra. *Would either need an autosave system, or obvious signposting to avoid people being blindsided
Just some food for thought