Agreed. These are pretty immersion breaking. I think before the reveal, the more vague ones should trigger like the "I have such a headache" is fine. Anything mentioning Father should be after the Act III reveal and should cease if you reject him.
I also think Durge's dream reveal in Act III should always result in Jaheira watching over your character as long as she's in your camp, not in your active party. I didn't have her in my party during the dream and thus never got that scene, and she wound up being kinda bugged and I couldn't tell her I was a Bhaalspawn like I could with the rest of my party. Because of that I didn't have the extended dialogue with her.
I noticed also with that Fist investigator during the murders quest, I could tell her I killed my sister before I even had the duel with Orin.
I love Durge and can't go play Tav, there's so much though that should be fixed before Larian stops patching the game...immersion breaking stuff like this and the lack of companion reactivity especially in Act II and III.