I have the Cat Leap in Parcool! set to consume essentially 6 full feathers with every use. however, if I use it when I have less than 6 full feathers available, I still perform the maneuver, and without consuming any stamina whatsoever. this also occurs with other maneuvers that would consume more feathers than there are available (e.g.: climbing up a ledge takes 2 full feathers; I am capable of it with only half a feather available, and that half-feather is not consumed).

it's not to say that I wouldn't like to be capable to over-exert, but if it allows me to do it, I would prefer it to drain the stamina fully and leave me in an exhausted state (as Parcool! does natively), and to forbid me from actions until the bar fills all the way up again.