Can't say that for sure, the bad ending is open ended. For all you know she was just upset at Geralt and didn't return to him. Or maybe she saved him from the monsters at the end.

I certainly does not feel open ended. Geralt is convinced she is dead. He is alone without any of his companions. He fails to follow the basics of being a Witcher (several lines of dialogue which tie Witchers to their swords). He is left alone in a cabin with a swarm of monsters after having been told by a Crone that he is following prophecy to die.

That doesn't sound open ended. Doesn't even feel like a cliff hanger.

That is the entire point I am trying to make. A good parent knows when to let go. Don't have to hold her hand and tell her what to do.

Which drove many decisions I made in the game. Telling someone to calm down does not fit under this umbrella. Telling someone to calm down is being parental? No, it's just telling someone to calm down.

Telling Avallanc'h that she should be able to make her own decisions is letting go. Making sure her voice is heard after the Battle of Kaer Morhen is letting go. But those decisions don't mean anything. They are far more pertinent, but meaningless in the overall arch.

No matter what you choose she listens to Avallach, masters her powers, and saves Geralt and wins the battle because of it.

I don't know where you are getting that. In the game we left and she never went back for any more training. If anything her and Avallac'h were at odds until he sends her back into the battlefield.

There's no additional "mastery of powers" ever shown in the game at all when I played it.