FWIW, I’m 6’3” and could easily stand on something 6 to 8” high and have plenty head room … popped up.
The problem could be it‘ll be cramped with the top down and climbing in and out, especially with the traditional flip up back window vs barn doors.
I went with a two level platform and a drawer in my back seat instead.
Edit: a few other thinds to consider… depends of course on your use case, but IF you want to make a more built camper inside the Decked setup will likely get in the way. Also, IF you intend to put recovery gear, camping gear, air up/down stuff, chain saw, etc or anything else you’ll need to use on the trail, you’ll have to open the back, and drop the tailgate. PITA on the trail, plus you’ll constantly bring dust into the bed. If you want to seal the tailgate, Decked may get in the way; for sure it will prevent a full Bedrug.
I have two lift up hatches, plus a utility drawer in the rear seat platform, which I use all the time to get stuff in and out without opening the back. Including being able to reach camp chairs, Maxtraxx, and shovel stored vertically against the cab bulkhead. IMO thats a lot more conevient at least for the way I use the truck and camper. YMMV!