Yeah editing the save doesn't really work as intended, I set Lone Wolf to 0 and saved the changes, when I loaded it up in-game I was missing a whole bunch of Talents. I didn't have Lone Wolf anymore and yet NPCs refused to join again.
I think the refusal might be related to this one bug, since even after you unlearn everything via the NPC in-game, NPCs won't rejoin.
But the missing Talents is related to editing the save, as alseT reported.