We went with Plan B: two Lazy Boy electric recliners.
The original Flexsteel sleep sofa covered one engine room hatch, weighed more than I could easily move by myself, wasn't long enough for me to stretch out in (while still in couch format), wasn't wide enough to keep both shoulders on the thing that way anyway, and was too big to find a place for during a temporary move anyway. Stretched out, the TV was in the wrong direction for me, too.
The two recliners offer infinite adjustment (the electric part, although that meant I needed to accelerate my planned inverter installation) and they get almost all the way flat, too. In that latter case, I need to pull them out from the bulkhead a bit, first, not a horrible price to pay since I rarely do that. And they face the TV
I can move each one, by myself. The local Lazy Boy store delivered -- to the boat -- and did the set-up onboard. The backs are removable, although once delivered and attached, there wouldn't be much reason in our case to dismantle the things. (At least not often.)
Just an alternative...