I was pondering the same thing as soon as I got my M4 sprint run Blur in the mail. Actually, I was probably thinking about it as soon as I hit "confirm". Unfortunately it doesn't appear to be a thing that anybody's regularly doing and selling anywhere. The inserts aren't as bad as I was expecting, which was the high-grit sandpaper like skateboard tape that Microtech uses (or at least used). But I'd definitely prefer something smoother and flashy. I don't really see the need for grip tape, and rubber will eventually wear away and maybe (but hopefully not) turn gooey.
BTW, @Kansaswoodguy , where in KS are you? Just curious; my mom's side of the family is from Larned.