At the end of the day nothing is going to get changed anyway.
They probably don't even read this board since it's not the feedback board, you don't see people discussing this stuff and getting up in arms on it on twitter/discord/reddit like you do with Karlach or Minthara so as far as Larian is concerned it's not even a problem. Hell, nobody has even made anything about it on their feedback forum on their Discord. I would but I'm not articulate enough to make a big write up on how shitty this being in the game is.
So either you decide this has ruined Shadowheart's character for you or you treat it as some optional fetish fuel some degenerate writer put him the game for himself and ignore it since you can go the entire game without her even mentioning Halsin even once.
Ye dw I only found out through the board anyway. Never played with Halsin in party, never will. He should be happy he's the only way (afaik) to save Thaniel or he'd get stoned to death more often. Just found it interesting enough to dig into while I was waiting for the patch.
