Quick summery:

Just like the L2 & R2 holding to switch hotbars without cycling through all your hot bar sets.. why not add a "Tapping & Holding" option for the Directional/Button Pad as well?

Ex: Hold circle for set amount of time to activate [Heal 3], Tap circle to activate [Heal 1].

[Heal 1] on Hotbar 1 and [Heal 3] on Hotbar 3.

Also have it where there is a small meter to tell you when the skill is ready or not on your visual hotbar that it is set to.