It's about time Shield oath and Grit become Abilities instead of Spells. (off-GCD)

[Saeno]

Give provoke the +1 for 5 seconds. Not enough to finish an aggro combo, but long enough to keep a dps from stealing. It’s still gives a margin for error in the tanks part, but not as spicy to cause a wipe because aggro is all over the place.

This is a very interesting idea and I do like it, however the only issue I see with this is that if a tank by mistake hits provoke while they have a debuff that increases the damage they take, like say Death Sentene in Unending Coil, it would cause a death to a tank simply for using a button when they shouldn't have. I believe for this reason, provoke does not work the way you've mentioned.