I've tested this with Brightsides and it works, you will retain the nonskid pattern but get added grip if you use the non-skid addative and some flattening agent.
I would agree with the above posts that Awlgrip or the two part Perfection (both made by Interlux) would be a better choice than Brightsides. You can't top coat Brightsides without sanding so you'd have to get it in one coat without thinning. Actually, I'm sure the same would be true for Perfection and Awlgrip with the non-skid addative, so plan to get it right in one coat, but it will last longer. Prep would be a good cleaning and de-wax wipe down with acetone or lacquer thinner.
At the end of the day I decided to go with Kiwi Grip after sanding the non-skid pattern flat and de waxing. Ultimately cheaper and easier to repair, touch-up, and recoat if needed. There was enough chips and other damage to the non-skid to warrant sanding it flat to begin with. I would bet that the Awlgrip and Perfection will last longer than the Kiwi Grip, but $110 gallon will do my entire boat and if I get at least 3 to 5 years out of it then I think that's good.
BTW, on certain sections of my C-22 like the pop top and the fwd hatch cover the non skid in the gel coat is not damaged, so I could still go the route of Brightsides with the addative but I haven't decided yet. Still working on priming my deck/cabin/cockpit.