One may wish to test-fire a round-butt revolver, in the relevant frame size, before undertaking such a project. It took me a while to sort-out exactly why I preferred squared-off grip frames and grips, across the board, but it finally became apparent that muzzle-flip was worse, with rounded-butt grips.
I was always more accurate, with squared K-Frames, and squared L-Frames, than rounded K-Frames. I noticed this in the Eighties, from my earliest days of hand-gunning.
I also noticed that I preferred the original squared-profile Ruger GP100 factory grip, Which I had been using since the very early Nineties, than the factory rounded-profile grip, which I did not try until 2002 or 2003. Not only was I more accurate with the squared grip, but I could not shoot the full-velocity Magnum loads comfortably with the rounded grip. I switched to the square-profile grip, on my fixed-sight GP100, which had been factory-equipped with the rounded grip.
Edited to add: To be clear, I was not writing about the Hogue grips, which became common on GP100 revolvers, for a while.