I have some strange ideas, but unfortunately, I can't implement them because I don't know programming.
Could mercenary characters and slaves captured by the Bison be added as standard party members? Equipment should only be compatible with a few specific texture sets, or customization is impossible. Equipment can only be modified by changing the color (for example, some characters with the same model and color change as the mercenaries).
Also, some contractable humanoid monsters could be added to the main party as permanent characters, though other than rings and bracelets, equipment wouldn't be available for the time being.
We could also try to unlock their sexual history lists and some sexual restrictions.
For example, succubi, angels, Marias, and even previously captured slaves could be captured and trained by the Bison, or they could have sex with characters like Lan normally. We could even transform special areas like the horse stables in the inn into prostitution areas. The girls there wouldn't be losing money, but would be working as prostitutes, adding to their sexual profiles.
Even enemies that capture female characters would try to capture them. While there's no CG, the few lines and the ever-increasing heartbeat are enough to make you incredibly excited. This way, we could get exciting teams like prostitute trainee succubi and former maternal angels. Their resumes reveal their rich sexual history, and they might even be carrying children from unknown sources while fighting alongside us.
We could even try to assemble a pirated Valkyrie team to play the game. After all, there are plenty of these female adventurer teams in the game, right?
Unfortunately, I don't know how to program, so I can't make it a reality.