Two factors pop up on heavy stippling - when it's more than the 18-20 lpi the military uses. One, if you are using the weapon for long periods barehanded in the heat, it becomes more than abrasive, it may actually create blisters. It's going to take some time and effort actually using it to see if - if - there are any hotspots.
Two, a lot of shooters now wear gloves year round. Soldiers do, they protect the hands working in the environment, which changes from rocks, bark, and aggressively thorned vines to splintered wood, masonry, and man-made barriers intended to create injury. How the gloves fit becomes far more important than the texture offered by the grip. A loose, sloppy fit inside the glove then becomes the critical surface.
While the size and shape of the A2 hasn't been my favorite, the vertical slotting at the heel, and simple checkering works well when barehanded, allowing some cooling effect with the tunnels transporting heat away. I recently purchased an TD Battlegrip for my AR project, it has stippling that I can already tell will need sanding down to a less aggressive texture. A simple application of fine grit emery strips in a shoeshine pattern will reduce it where needed.
Before jumping on the heavy stippling, think thru the specific increase you want, and where. Like removing the bump on the A2, specific improvements can be made, without resorting to a wholesale method that just may be much more than was intended. Consider how gloves play into it, too. It's a very custom fit - no one can say what worked for them will work for everyone, just like your teammates' boots aren't likely to do any good for you.