for the last part of the stage -

Jump to the 3rd rock to spawn the moon and jump back Jump to the 4th rock and land on the right side to punch the butterfly. Landing on the right side will let you instantly kill the butterfly. Landing on the left side wont give u the distance to kill it. Wait for the moon to catch up then jump to the last rock and again land on the right side to instant kill that butterfly. Then just wait for the moon to catch up.

Hopefully this saves more runs from this awful stage. Still no good way to guarantee the part before this, especially if you get a bad pattern or the bird despawns. But at least, if you can set this up, it takes away the butterfly RNG.