When you deloft an iron/hybrid in order to hit a stinger or punch shot, is there a formula or relationship between the amount of angle delofted, and approximately the angle to aim to the right/left?
No formula, and I’m not sure why you think you have to aim left or right. Ball flight is controlled by the path and the face angle at impact. I grew up in West Texas and trust me, we learned to hit “stingers” very early, with every club in the bag! Ball back in the stance, hands forward, finish low. The clubs path and the face angle at impact will determine if the shot will be straight, a draw or a fade. You can hit low stinging fades, draws, hooks, slices, all predicated by the club path and the face angle at impact. There’s no formula, just the need for proper technique and practice.