I’m extremely skeptical that’s correct... at the very least the heal kicks in way quicker than that.
Anywho, you don’t have to only cast it right in the middle of combat. Run around the corner when you have a heal or endurance emergency. The game is much more tactical than just standing in melee executing a chain, if you try to play it that way. Either way, in game performance has not been bad.
If you don’t need the heal enough to take it as is, and don’t see yourself executing any maneuvers more tactical than sitting in melee, then where’s the problem?