Pure GOLDI struggled with appropriate trigger reach on my 642. I really though that the cure was a boot grip with a covered backstrap. With the stock S&W stocks, my thumbs would interfere with the end of my trigger finger near full travel.
I belt-sanded the pinky groove off the bottom of a set of Uncle Mike’s Combat Grips. I tried Pachmayr Compacs. I tried Hogue grips. I did the Taurus grip mod.
After all that, the best and most consistent performance I got on the timer was with magnas and a BK Grips grip adapter (basically a polymer T-grip). I didn’t need a grip that was bigger, I just needed a grip that forced me higher on the backstrap while providing strong front-rear index points. Seems counterintuitive, but the short and narrow stocks somehow keep my thumbs out of the no-no zone. I get bit occasionally by the cylinder release, but my trigger finger can do what it do.
Not a fun set-up for shooting anything other than wadcutters or slow LRN loads.