I'd agree that the higher
hatch location on the cabintop is going be a dryer one, though in rougher going any deck top
hatch is going to get heavy spray if not green water.
I suspect the actual location of the hatch will have more to do with the interior layout - i.e. where you need the light, ventilation, or egress.
It's easier to haul a sailbag up and out of a foredeck hatch.... but this is not the consideration it was before roller
furling.