PoE2 has a system of companions and sidekicks, where you can have companions with some story and dialogue but being clear they aren't full companions? BG3 could do a DLC of those and include characters like that.
I don't really see Kagha working? either she runs a grove and is happy, or you're the person who overthrew her so why would she like you?
Viconia could be great, if you trade her SH she joins your party to cement the alliance? meaning you're not just giving away a companion but exchanging one for a more powerful cleric?
Nere? Pretty much half the True Souls could be saved and Nere would be great because he'd still be a jerk.
Thulla (the boots having gnome)?
Isobel and Aylin, maybe not Aylin as she's powerful but definetly Isobel. They're in your camp anyway.
Someone helpful and good who turns out to be Orin or one of her henchmen in disguise who turncoats at a pivotal moment?
