Like I said, though....if you sighted your bow in ....in a particular position....and shot it in the same position each time......what difference would it make if that position wasn't level?
I say none. Actually.....if you sighted your bow in and it wasn't level.....then you shot it level....you're screwing the pooch.
But why would you do that? The whole point of having a level is for it to be plumb to the bow so you can plumb the bow when you're shooting.
IF you sighted in the bow with the bubble off at one distance and do all your shooting with the bubble in that spot, then yeah, you're right. If your sight has pins that are individually adjustable for windage, then you can even sight in and shoot various distances with the bubble in the same position. Problem is, they make few if any sights like that any more.