Having an ending where you actually can get reversed and "win" by being a star witness against the antagonist as you bring down their evil empire should definitely be on the list of multiple endings imho.  However, it should not be easy as the antagonist(s) will try harder and harder to get you to succumb.  Perhaps even have some minigame challenges you will have to complete to get this route.

Should also have some early bad endings spending too much time in a seedy area at night gives you a chance for a bad end where you are taken.  Perhaps doing too much teasing of the friend and/or sister can lead to either a bad end or a lonely ending.

Some acceptance paths were you choose to accept the changes and either have a full change or stay top only.  You could also have some dominant/ submissive paths for both those options which can have friend or Eve as the opposite in the relationship depending on which path.

I haven't played in a while so I don't know if it has changed but you may also look into having some type of random factor to the game when it comes to the first email you get at the beginning.  A boon that helps with cash flow or hurts cash flow if you give the address.  If you don't you either have someone who pursues you in anger increasing chances of bad endings stated earlier, or may rescue you if you do fall into a bad end.  They would be random and be revealed about a week or two after the email is dealt with.

Hi, I really enjoyed this game when I first discovered it. Played through most paths, but I started to lose interest when it detected that the 'transformation' process was heading towards bimbofication (or at least that was the vibe the game was giving off). I think multiple, discrete endings should be the end goal soi that player choice actually has some meaning. I personally would like to see a trans ending that doesn't involve bimbofication, where the MC can embrace their masculine and feminine sides.