My whole point is that PC has had *months* without the tadpoles protection at that point and he doesn't force them to join him. Neither does he attempt it at the party.
I think that it's implied that Tav, who recognized how awful he was and thus broke up with him before he could compel them, knows they can't really see him or he will compel them. These months they just didn't see each other (confirmed by the dialogue, by the way). Maybe Tav even run away from him on purpose.
Once again. He can't compel them at the party. Otherwise all the other companions will kill him for it. He can only be there with already compelled Spawn, because, obviously, he told them not to tell anyone they are with him against their will. Hence, you can ask for freedom, he will deny it at the party, but you can't ask other companions for help, because you are already compelled not to.
And all of this doesn't even matter anyway. He still forces Tav to stay with him in the end, when they want to break up. It's canon. Period. It's like to say that a man who killed one person isn't a killer, because he could have killed two, three, four people, etc.
Just because he didn't do it in some cases doesn't erase the fact that he is willing and able to do it.
