I am with the Skipper.
I think that if it does not impact operation, I wouldn't mess with it.
I had a revolver with a similar fault only it was on the outside of the recoil ring. The hand channel had been milled just a bit too deep.
It was on a brass frame revolver and had some years on it so it was probably of a vintage before CNC.
I have since parted the revolver out and still have the frame. I retired the pistol, not because of this flaw but because the arbor got loose.
You might take a scribe or a small probe and find out how deep it goes. As long as the void is limited, I like the fill it and forget it option.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson