Make Smite’s charged attacks have limited uses (like Ogryn’s Big Friendly Rock) and then rework Smite’s uncharged attack to be an insta-stun against a singular enemy with the typical unlimited uses. Charged attacks would end when the Smyker either stops the flow of their Smite manually or reaches critical Peril. Let’s say (for example) that it has 2 charged uses with a 60-second cooldown per replenishment, taking a total of 120 seconds to fully replenish them both.
That way, Smykers could use an uncharged Smite attack against a singular enemy at any given time but would be left vulnerable to any enemies that they haven’t stunned. The charged Smite attacks being limited like Ogryn’s Big Friendly Rock would completely nip charged Smyker spam in the bud while forcing Smykers to actually strategise about when and where to use them.