I had sanded my SO picks a while back without too much noticeable difference (I don't really use SO picks much anymore, but I never found them to be very "sticky" in the keyway to begin with)
But after using some of raimundo's rakes very recently (now
those things glide!) I gave it a shot with my Petersons, too, and got much better results. "Glide" really is the perfect word for it.
So, I've been a bit sand-happy lately

Looking at the Rytans even more carefully now, it sort of looks like it is 2, and not 3 pieces of steel that have been fused together, although for all I know there could just be a line down the middle of each of their picks on a single piece of a steel. It's very hard for me to tell, even under magnification. I guess my worry is just that if the two pieces aren't evenly sanded, I might have strange results, or that I might even weaken the seal between the two. I don't know, I'm just thinking out loud.
I'm also hesitant just because I really like my Rytans. If no one else has tried sanding a Rytan pick, what I may end up doing is just buying another single pick to use as a practice run / to make sure nothing goes wrong. They're cheap, so it's probably worth a shot.