On a magazine it appeared, so using it as basis:
Threads appear as articles in the page's source code. Microblog posts appear as blockquote.
So you should be able to hide them, at least with Ublock Origin, with domain_from_the_instance##blockquote, e.g. for mine, thebrainbin.org##blockquote.
melroy@kbin.melroy.org 11 hours ago
Do you like the setting to be opt-out so "all" will be the default. Or should we make this combined frontpage a opt-in feature (default will stay "threads")?