3.0.0 removed a lot of rooms for the original character (DLC don't have many changes)
Level 1 - No Change
Level 2 - In the first room with the wheel, the load zone is a little earlier (Applies to some DLC as well) (Saves 5s)
Level 2 - The room with the key dees has it's first half cut off (Everything after the first bridge is still there) (Saves 35s)
Level 3 - The diamond shaped room before the room with the electric saw blades has been removed (Saves 5s)
Level 3 - The room right after the cannons and before Flamberge with the Poppy Bro has been removed (Saves 5s)
Level 4 - The diamond shaped water current room with the switch and the cannon has been removed (15s)
Level 5 - Extra Planet Delta has been removed entirely (The level with the friend doors) (this doesn't apply to any DLC characters who normally have this stage) (Saves 55s)
Total Save - 2:00 (35 for DLC)
I'll add images later