A passive benefit after X eather stacks used (don't need to be 3, 4 or 5 seems better). That's pretty standard, INV already got something that look like this (also, it can be applied to proc based trait all healers have to make them more consistent).

The most simple gain could be an auto crit on the next spell casted, since it'll also make the crit part of SCH something that can actually be played with. It could also enhance the next spell cast in a specific depending on what you chose to use that could (suppressing the crit part of addlo and succor at the same time) that would make enhanced Broil 2 something you could want to cast over addlo + deployment tactics.