Like the ideas of NPC relationships, though I find the requirement of working the same workproduct a bit hard in the mansion as most of the time I don't have people working the same resource.
There have been a few bug that seem present in the latest Linux version of the game (0.10.3b). I applied workarounds on my version, tried to make a mod to do it but could not figure out how to update game_party.gd functions, so I'll just list them here.
Bugs I was able to fix in my game:
File game_party.gd:
func relationship_decay: 163: var value => var value = 0 # if reldata .value is 50 or 51, value will not be set func find_all_relationship & relationship_decay: relationship_data does not seem to delete entries containing characters that no longer exists these functions lead to accessing value from get_char_by_id to non-existing characters (null). This also leads to no relationships been shown in the overview, from SlaveSiblingsModule.gd:build_relations func _in_same_location: for the most part, in the mansion_location a lot of these are testing if workproduct are equal. For the farm work='produce' job, it seems to not clear workproduct, my save shows one produce job with workproduct='', another with workproduct='wood', so they are not in the same place. I fixed this by clearing it in the CharacterClass.gd:set_work, not sure if it breaks things.