Mm, are these the suggested posts that you can snooze for 30 days? This extensions blocks suggested posts after reaching the "You're all caught up".
The way to get rid of all of them is to snooze for 30 days posts in between your subscriptions and then the extension will block the scrolling once you've catched up with all posts from people you follow.

PS: I'll try to see if I can update the extension to block those posts as well.

Update 2025-12-13: Sponsored posts in-between posts from people you follow are now also blocked. If you still see them try snoozing them for 30 days and use an ad block in addition to this addon.