I armour all my boats when I try to sell them. Seriously though, waxing has no affect on hull speed. At best it slows a boat. With a sailboat hull, the fastest treatment is a fine grit sandpaper. The effect is similar to golf ball dimples, but on a micro scale. A waxed sailboat hull has air bubbles sticking to it, which slows it. I am sure there is some similarity with a plastic hull.
If you are looking for protection versus speed, then I do not have any knowledge, only opinions. I would guess wax could help with sun damage, but then you might be more likely to damage your car when it slips from your hands and bounces off your hood. There can be no protecting boats from rocks, they are too abrasive. Your pride and joy today will be outdated or broken in three years, so don't bother protecting it.