I honestly think you'd spend less time with un-optimal amounts (overshooting the amount you need and stuff) compared to having to make everyone go on a round trip activating everything (sphere grid travel time makes me want to punch people), even if it means going through 5 extra repetitions for 10 extra spheres*. You have so many extra spots that it doesn't really matter, unless for some reason you're aiming for 99,999 hp as well. (And even then it's arguably faster to spam stuff first to cap everything else THEN work out what you need to clear just because you get to that point so much faster)
*Except Magic/Jumbo Flan, of course. Jumbo Flan can go die in a barrel.
edit: the actual answer:
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