Hey Rich,
Interesting idea. I remember reading that in Bud's manual at the time we were repainting, but there wasn't a specific product recommendation, so whenever I found some pool deck coating, I always seemed to be able to find negative information about it from the marine community; (ie poor adhesion, chemical stains, not textured enough, too textured, etc.)
How was the prep for the SherCrete? Did you prime prior to application?
As all of this over factory nonskid, well that shouldn't be a problem as long as you have been able to prepare the surface well. Probably use a wire brush attachment that will allow you to get in to all the grooves and you'll be golden. Just be sure it's stainless or brass bristles to avoid rust flecks windup up everywhere in a few weeks.
-Aaron