Kalista Ult QOL

So, 50% of the time the kalista i am playing with ults with me as support, i wiff it because i press the wrong mouse button. I use all quick cast, so i never think to use the right click to do pretty much anything. It only takes me half a second to get it right, but often time that messes up the play. Im sure i could get used to it if i played with kalistas a bunch, but that isnt much the case. So long story short, could both mouse buttons activate kalistas ult? it would be nice.