I found that the painted decks and roof can get very slippery, even wearing Crocs, which I find are very grippy. I have tried a non-slip additive in the Toplac paint with limited success.
This year I am expanding my "use ordinary paints" experiments. I found that Dulux Weathershield paint lasts extremely well, even in a marine environment. It is water based, which makes application much easier for a bad painter like me. I always wreck brushes. With a water based paint, I can leave the brush in water and it is always ready. I painted the whole of the super structure with Weathershield for last season. It lasts perfectly well. Possibly not quite as opaque as Toplac, and not so hard wearing. On the edges of cockpit benches it has worn through where I brace my feet. But otherwise perfectly durable and very easy to touch up.
I painted my outboard well blanking plate with it, and that has survived without any deterioration at all, even though about half of it is underwater all the time, when stowed, and all of it is underwater when in use.
So to address the non-slip needs, I have used Sandtex masonry paint on all decks that I walk on. I used it in a dinghy very effectively and it is meant to be used on light houses, so it should be durable. It is very matt, but not a rough as I expected, so I don't know how non-slip it will turn out to be when wet. But I do like the look of it. If it proves durable I might switch over to it, rather than the weathershield, as I do like a matt finish. It is also water based which makes cleaning up and brush maintenance very simple. But only sea trials will tell me if it is really suited to a boat.