this is the weirdest thing. I just practiced a dozen or so shots set up exactly like this today (cuz I have trouble with 'em, duh), then I come read this thread.
I kept consistently undercutting the ball, and I was always trying to spin the ball in because I wanted to use low outside to keep the cue ball around the kitchen line.
On relatively difficult shots you need to avoid the use of english at all costs. By using english, you introduce squirt/throw making an already difficult shot that much more so.
If you ABSOLUTELY HAVE TO use english to avoid disastrous shape then you should probably play safe in the first place.
As for curing your "Back Cut Blues", if you have a proper aiming system, then it makes no difference where the pocket is relative to the angle created by the CB/OB.
My aiming system does not even require paying much attention to the pocket (personal modification...and improvement in my opinion...of the "Houligan" system.)
But regardless of your system (which you indicate is not working) try a progressive drill. Set up the exact same reverse cut angle starting with the CB/OB close to the pocket and then just keep moving them further away.
Finally on aiming, it is TRUE that some all-time greats may not have even had one but rather just developed an intuitive FEEL about aiming. But A) those are people with SCARY eye/hand coordination who B) practiced/played 80 hours a week if not more.
Regards,
Jim
Edit: And some of the greats DO/DID have aiming systems but would not even THINK about telling anyone about them for obvious competitive reasons. Some even LIED about LOTS of things they did and didn't do. Willie Hoppe was one such player.