The only preventative for pressure sores is reducing pressure. Skin care helps the skin but pressure sores develop in the muscle below the skin, like a deep bruise. Skin sores, other than raw spots from friction, are usually the last thing seen with a pressure sore. The first sign is pain, then discoloration, either bruised darkness or redness. Break down of the skin is last.
Both the chair and the recliner need to have a ROHO cushion. I am not certain that even a ROHO can overcome the effects of sitting day and night every day. In addition to the ROHO, there needs to be full support for his arms to prevent shoulder subluxation and easy dislocation. The ROHO cushion will lift him up higher so, if he uses the armrests they have to be padded to raise them as well. Most often though the arms and hands are inside the armrests so the elbows need to be well supported. Also, even with the feet up in a recliner, swelling of the feet, ankles, and up into the lower legs has to be considered. Most recliners have the weight of the legs on the recliner's leg rest. That puts all the weight on the calves and that affects the ability of blood to circulate back up. Newer recliners may have better leg support but not all. A hospital bed with the head elevated would be far better for his circulation, but would still require a special medical quality pressure relief mattress or mattress pad. Since he will be sitting or semi-sitting even in bed, using a ROHO wheelchair cushion in bed would work well too. BiPAP is sometimes and understandably refused, but using BiPAP would allow him to lie down as well as turn on his sides. Switching from sitting up to lying flat to turning from side to side will prevent mucus from settling in the base of his lungs, thickening, and further reducing his lung capacity.