Anime

I've watched Part 1 and 2 of AoT season 4, trying to understand Part 3 release schedule.

I see The Final Chapters Special 1 released back in March, is this Part 3 or some extra thing separate to part 3? Are there more specials/parts? Kind of annoyed how they stretched one season for years, and releasing it in the most confusing way (Season 4 part 1, part 2, part 1 of part 3...) almost makes me not want to watch... (almost)

Pls help me understand, thanks!