I know Larian listens to feedback but I just have a feeling in my gut that whoever wrote Karlach has severe author-brain and will force feed us this stupid fucking forced tragedy by any means nessicary.
Karlachs story fucking RADIATES emo 13 year old who saw The Notebook for the first time.
(sorry for double posting)
Even assuming this was true (and i hope it isn't) her arc still needs fixes to work as a tragedy with no way out (dialogue changes, item removals, etc.) otherwise it's just an incoherent mess. If someone was really hellbent on making her go boom, they should have accounted for that in dialogue and obvious stuff still lying around (enriched infernal iron anyone?) so even if this was true they didn't do a very good job at it. Tragedies can work, and could've worked for Karlach if they wrote her like that to begin with (which i believe they didn't). That's why i believe a fix is more probable than what you suggested, or maybe it's just my wishful thinking.