Moderate sleep apnea syndrome and sleep on the back and sleep home appliances

It was news that Shinji Mizuta, a comedian combination of Japanese beef, had been tested for sleep apnea syndrome (SAS) in April this year. Mr. Mizuta has been suffering from sleep apnea for four years, and recently a test at a specialized medical institution says that it is a moderate SAS that is close to severe disease. Severe SAS is covered by CPAP therapy, but is not covered by CPAP therapy for moderate disease. This is because in severe cases, the risk of related diseases and death is very high. However, moderate disease does not mean that symptoms such as daytime drowsiness occur. Then, what should I do for moderately ill patients who are having trouble with daytime symptoms?
Mr. Mizuta mentioned earlier made a mouse piece to improve the bite. In addition, a doctor told me, "Please carry a backpack and sleep." The mouthpiece lifts the tongue by shifting the bite to improve apnea, but the effect may be limited in moderate disease close to severe disease. The main cause of sleep apnea is suffocation due to the subsidence of the tongue due to gravity (the bottom hangs in the back of the throat), but in the lateral lying position (lying sideways), the subsidence of the tongue is reduced.
If you sleep with a backpack on your back, you will not be able to turn on your back, and you will inevitably be in a lateral position. However, the backpack is in the way and I can't turn over. It is said that people turn over dozens of times a night, and it is not preferable to continue turning in one direction all night.