I believe Gina referred to ours, and we sleep left-to-right and I will step over my wife's legs to get to the bathroom as long as I am mobile enough.
She sleeps closer to the bathroom with head curbside so that it is easier to curl her legs up to avoid being trampled (the bathroom sticks out more than the clothes cabinet).
We at first added a 4" foam mattresses to the original cushions. Was comfortable, but too high. Removed the cushions and added an eggcrate and 1" memory foam to the 4" foam. Bonded together with a spray adhesive for foam. My wife sewed a cover with velcro or zippers to help getting them laundered more easily. Two sets of twin sized so that getting them out is relatively easy. Fine for us.
I have two battery
boxes, AC installation, subwoofer, converter, and amps under there, so I tried to make it easy to get things out to check and work on them. Therefore I cut nine planks of 1x5 inch wood to serve to bridge the gap under the matresses, numbering them for quick installation because they needed to be of slightly different lengths. (The are actually 4 1/2 inches wide and 3/4 inches thick of course. I used KD Douglas Fir because it is exceptionally strong and stiff.)
This setup is at least as comfortable as the bed in our home.