A rear corner bed is just about the only way to have an always-available, nearly queen size, bed at floor level in a small Class C without slides.
The DW has no problem using our rear corner bed because she is the only one who sleeps in it due to her needing the whole thing to spread out with her bad back. I use the cabover queen, which is easy to get into due to the raised floor of our basement design coach and it's stock ladder with wide steps that Winnebago supplied.
There is no need to "make up" the corner bed. We just use a foam topper on the corner bed and then wash/change it's fitted sheet periodically. The fitted sheet is easy to put on/off by curling the topper's corners towards the foot where we stand, as we stretch the fitted sheet's elastic edges over onto/off-of the underside of the foam.
Use of the corner bed this way is not difficult at all, and what effort it is - is well worth the advantages of a small Class C with no slides.