That's interesting. I didn't watch the video. It looks like the same layout, but they're using the extra 3 feet of trailer compared to mine to make the bed work differently (this configuration also gives you more storage underneath - out bed tucks into the storage compartment when up). On our previous trailer, the bed shape was weird - longer and skinnier than a queen - and we cut the side off a foam mattress and tucked it on the head of the bed so that the seam was under the pillows. I really liked that bed because it had extra length, and I didn't mind the little bit narrow. You could cut a foam mattress in half to fold like that, but I'd be nervous that it's heavier and floppier, so it would be hard to unfold, and that if I've got a split right where my butt is that it would separate. A nice foam topper would probably work just fine, though.
I just found out I'm getting a foam mattress for father's day, so we need to figure out how to support the extra 9 inches of length of a regular queen mattress and hope we can still fold up the bed!
2019 Wildwood XLite 19dbxl
Still Learning Camper Life