I like the ideas, but honestly, I really think it should just be reverted wholesale.

Dropping Noxious Gash was losing 10% on, like, one or two GCDs until you go "oh crap!" and reapply it again. Losing Noxious Gash for even a Reawaken is still only slightly more catastrophic than one or two canceled casts on a caster.

Who cares if they can mess up? That's fine. 20s applications, 40s caps was fine and players who didn't like it would've gotten the hang of it eventually or landed somewhere else.