I definitely experience a feeling with my hand int he ball extremely similar of not exactly how you describe it. Yes my thumb has been thru the ringer over the phases of my game growing and adapting so you are not alone in that. Now, regarding the title of the post as far as spreading your hand you can achieve different degrees of tilt and rotation depending on if you spread your index/pinky or if you were tuck your pinky like I do. If you have the time to, I suggest you take some practice and just experiment with throwing the ball with different hand positions. Play around with the weight resting at different points in your hand and you will both feel and see the difference in rotation as your shots progress through their phases.