It wasn’t too difficult to manage for Tin Star. I broke each relationship up into roughly ten point chunks and made sure to keep it open ended on the higher and lower bound. Then I inserted several early-outs in case the person in question hadn’t been met yet, had been killed, or was in a romantic relationship (Different descriptions applied).
The question for me here is, what kind of world am I trying to model? For the original Marine Raider, there were no relationships per se, since Marines obey orders. Similar thinking applied for Apex Patrol. For Tin Star it was the long arc, an accumulation of interaction over ten chapters, and therefore it made sense to have all those subtle descriptions to illustrate that personal development. In Shadow Horror there are really only two other characters and the situation is too intense for much long term development.
But if you are writing a romance then lots of detail and a gentle but steady gradient seems appropriate. For a High School saga friends should be able to have a falling out one day and bounce back the next week. An apocalyptic tale might be better represented with a brittle percentage system to illustrate that trust, once broken, is hard to regain. A redemptive story might likewise benefit from the reverse by illustrating that a good turn can right innumerable past wrongs.