Okay y’all, here is my RANGE REPORT.
1) I stayed with the stock 16# recoil spring, but went up to a 25# main spring. Stock may be 23#, but my Para single stack seemed much lighter than that—maybe 19#. The slide was then much harder to hand cycle with the hammer down. Note, with that stiff hammer spring, it was a bear to get the back strap cross pin back in place. It took four hands and two rubber bands to put the darned thing back together.
2) I removed the bulky rubber finger groove grips, reinstalled the stock plastic grips, and added some scate board tape to the front strap.
3) I removed the pretty, lowered-and-extended thumb safety, and reinstalled the old half moon style safety.
4) I added a Wilson Shok-Buf.
5) I changed my grip from a high Thumb-on-Thumb-Safety grip to a thumbs down Crush Grip, or a high thumb “Sig Grip”—that’s with the right hand thumb near the thumb safety, but safely off to the side, resting on the base of my left thumb.
RESULTS
Success! No more thumb pain! Even with hot 230 grain handloads, and full power defensive hollow points, this pistol is now a sweet heart! I shot a 50/50 Dot Torture drill at 3 yards with no pain while shooting or afterward. I am pleased.