Hi the tray suits your Frontier really well. Was the tray made in the US?
Ive only seen them made in oz in big numbers before.
I like them for the same reasons you outlined,less metal to damage,more surface area as well as less to rust and easier for DIY mods and repairs.
I have a 75 series landcruiser that had a steel tray. When I got it ,it had a canvass stratched over a steel frame.
It worked well but I kept ripping it under trees and occasionallly low carparks.
I ditched the steel tray for an alluminium type that weighed 200lbs less.
I wanted something for camping with the abilty to stow a fair amount of gear away out of sight and came across the camper in the local classifieds.
I was going to suggest you put a draw underneath the tray but I see you have already discovered that trick:Astrologist:
Under the tray is also a good place for a water tank as it keeps the centre of gravity low and lessens the effect of water rushing to one side on an incline.
I plan on using the space for 2 spare tyres
Another suggestion is to use 1/2 rubber blocks between tray and frame.
my landcruiser with tray and camper(has tent under grey vinyl)