A few suggestions.
1 - Simplify the gym minigame. I find it several orders of magnitude more difficult than the others.
2 - A scene between the main character, Anna, Charlotte, and Phoenix after bodyguard quest.
3 - Change Emma's lines after Mario's arrest or at some other point, similar to Katarina.
4 - A way to spend a huge amount of money even without much effect on the game. The main thing is to feel like the money is going somewhere, not just going to the limit.
For example, after Mario's arrest, you could approach Emma with a proposal to make the world a better place and give her money to do so. Although, in theory, this is also possible in sharing route (?). It could include a scene, but it's sufficient without one.
5 - Create a means that makes dominant vampires obedient and get caught in an abandoned house to use it.
6 (very, very suspicious) - Create a super condom using the best science in the world, which will allow Emma to experience double penetration from a lizardman. A variation of this is the protagonist taking a futa pill (as strange as it may sound) and double-penetrating Emma. Or, inspired by the example, double-penetrating Anna. This idea could also include a super lubricant that allows Emma to accommodate the Bigfoot apparatus.