Double berth
I am not sure if it will help you, but I designed a bunk conversion for my E27, which works very well.
I built a table, which has a retractable hinge on the head wall, and this drops down to fit onto the sofa, with another retarctable hinge at that height.
I have two screw in legs for support.
The system works very well, and was fairly easy and economical to build. I would be very happy to send you pics if you wish.
Ian