This was something I was using in my attempts before I had to stop running the game since it kills my old man wrists now. Doing this was saving me about 5-6secs. Since I usually die at the reverse gravity part in the final stage this was a net gain for me and the 5th hp bar isn't needed.

If someone can figure out how to get the extra life extender to appear on the mini airships then this becomes the definitive way to do this part since you can then do stage 5 deathless with no time loss.

Hopefully this is helpful for someone