Thing is, there's no term used to define their relationship in the script - IMO for the better, makes the interactions feel more natural. Anyway, so you can't just add a function to replace every 'friend's mom' with 'landlady' or anything else. Want to make it an incest game, you'd have to go manually modify dialog, and probably add some new lines, too. And keep doing it for every new release.This look extremely good !
An obvious request is for a mod that changes the main MILF's relationship to MC to "landlady".
Technically not that hard to do, since the script files are just sitting there unpackaged. But would require some creative input, which is not everyone's cup of tea.