Not a grip "pro" but when I shoot more relaxed I shoot more accurately. I don't know the science behind it, just know what my results are.I've shot 45acp 230gr a lot, I shot 147gr 9mm a lot, as well as 124gr. I really don't notice much difference between the two.
I do shoot a lot of full power 10mm, and 44mag. Maybe I'm just used to the recoil from those and don't notice it as much with the 45acp.
Off subject a little.
I learned something over the years. I have a very strong grip, and I found I was over gripping if that's a thing. I found that when I put less grip on the handguns I shot more accurately.
Why would that be?