What kind of bed/mattress/overlay do you have in the meantime? At the least you should have a high quality foam overlay (latex or furniture grade) and should be able to sleep supine for at least a few hours at a time. Are you already in a hospital bed?
If your shoulders are subluxated or at risk, a bed that turns you is not necessarily the answer. Make sure your arms are bent and supported when you are turned. There are pillows with shoulder cutouts (including PAP pillows) that might feel better on your side but they cannot compensate for weak joints. And I would certainly make sure your shoulders are protected both in your chair and in bed (arm completely cushioned and not pulling the joint out of place).
If you feel like the Roho is "golf balls," something should be changed. Do you have the right size cushion for your chair? Are you very thin on your butt? Are there indentations on it after sleeping/sitting? Are you sitting in a stable position? You might need more postural support. Also, are you getting a lot of shear when transferring?
Not everyone does well with the Roho; there are other options, e.g. Vicair, Stimulite, gel/air combos. If the VA is dragging its feet, could you be seen at a local seating clinic (often serves the spinal cord injury unit, among others) at a regular hospital? They can do pressure mapping and determine whether the Roho is right for you and if not, what could be.