please note this though:
https://social.growyourown.services/@FediTips/112242598452254728
a personal block is not like a server block
"It hides their posts from you, but does not hide your posts from them"
so even better than what i outlined above, you need to speak to your server admin and demand they block threads at the server level, which means a true block
example-
@Gargron, please:
you really need to block #threads