First and foremost, good on both of you for getting out and putting the time in to work and learn something! That's the greatest thing you can do to improve skill!
That being said, I'll caution you from my own experience about the path you're going down. I made the same discovery you both did a few years ago that by relaxing my dominant hand and increasing tension with my support hand that I could shrink my groups. However, 2 things eventually happened:
1. I hit a plateau on my group size shrink
2. My ability to control the gun at speed went down the drain.
This is where I get back up on my "neutral grip" soap box seen here (among other places):
https://pistol-forum.com/showthread....l=1#post586360
You can (and should) learn to develop a grip that will provide you with great precision at distance and also great presentation consistency and recoil mitigation. That is the place of grip zen. The problem is, nobody can teach it. You have to figure it out yourself with rounds on paper. @
karmapolice and I have both been down this road. Both of us paid good money to stand in front of a world-renowned instructor to have him tell us, "yep, your grip looks good" only to find out later that it really wasn't.
Sight alignment has to be good, trigger press has to be good, grip has to be good. You can fudge one of the three and still get by, but when you get all 3 working together, that's when you'll really hit your stride.