The whole rule does seem a bit wonky and open to exploitation, especially empowering yourself on skills checks when you've got a bit of time and space to prepare, and are willing to go beat up some random farm animal or summoned creature to get yourself warmed up. Even if you're only doing 1d4 base with the bite, add a combat superiority dice from Commander's Strike and an inspiration dice from a Valor bard's combat inspiration, and THEN roll your ability check to pick the lock or persuade the prisoner into talking or whatever. Absolutely blows the roof off the bounded accuracy curve.