I used to paint interior as a young man. Still have the touch.I will tape off the non- skid now to do the white separation where a PO got lazy and went outside the skid(sigh).But only there.Will be inside for a pro to spray one winter soon.Birds don't care, a tarp is advised till it dries
Depends on technique. I've seen a couple of Kiwi jobs, and it can look and feel really good, or it can be too rough, with lots of places to collect dirt. I guess one needs to practice a bit before doing a whole deck.