Granting you higher levels of immortality...

Samus can now only transfer health to reserves.
Samus can't transfer if health is lower than a value you set.
Samus transfers health until max reserves, not enough health, or you move from the digits.

You can't select items from a different list when reserves are set to manual.
You can't select manual to transfer when reserves are set to auto.

The more health you keep in your reserves, the longer you will stay alive.
Maybe just an interesting add-on to your next vanilla playthrough.

I was aiming for some form of "last stand" & "permadeath" if you died & the counter wasn't reset.