That's rough, I was annoyed at the hellthread a few months ago, but I wasn't getting death threats in there. 😔

IMO this is mostly a technical problem - It shouldn't be possible to add you to a thread and then spam notifications forever. Nostr clients need to step up on this.

So far my best experience with blocking spam and trolls is on Coracle - Coracle hides replies to people you muted by default. There's also web of trust filtering on comment replies, if you set WoT to at least 1 one of your your follows need to follow them in order for you to see their posts. This is mostly for fighting spam, but this guy who's harassing you managed to get a -14 score just by being an asshole.

There's some problem with hellthread on Coracle as well, but I found that if you mute the thread in another client, Coracle will respect that. So I used Nostter and "Leave thread" button in notifications to do that.

Hope that helps, please don't spend too long on corporate social media, I need my Carl fix. 😁