This is a really great plugin, and has a ton of great features, I would highly recommend it, and I can’t wait for version 3.0.0, I also have a small suggestion: per-world gravity, you can change the gravity of worlds so entities like player and items will float around (at value 0), or be able to jump really high, and more.

PlayerModification [Modify per-world players' Health, Movement speed, Old PVP mechanics, and more] 2.2.8
Modify per-world players' Health, Speed, Old PVP mechanics, Allow-PVP, and more]