The game is still in alpha perhaps that is an idea but the main story isn't even finished yet.
Really the issue is that affection isn't actually tracked. Affection is instead per-girl, and is arbitrarily set to a new value when a waypoint is reached. For a few characters, this works well enough. For every character, it would require a new system or manually adding those waypoints to each character's events.
As for the mansion, it's just not feasible AFAIK. A new area requires a lot of coding, and something so (relatively) minor would take up a lot of time that could instead be spent expanding the already-extant game. Your best bet is to check the Discord and see if any modders are up for the challenge.