Originally Posted by
Absurdity
It's similar but where I think that it doesn't fit the "frictionless" design philosophy is that it would be a lot more punishing than those two. Even if you mess up your gauge/MP management you have fallback options that you would simply lack if you were to for example reduce your own max HP down to 20%.
If you spend all your oath gauge before a buster you can substitute it with other cooldowns, same for emptying your MP at the wrong moment.
If you reduce your HP to 20% right before a buster, only cleansable by yourself, then no amount of other mitigation options is going to save you, besides maybe your invuln.