I read the sutta a long ago, and wondered why this does not mention sleeping on your stomach?
Eventhough, side sleepers tend to have pain, side sleeping keep you away from comfort a bit which helps you to awake easier.
You can be mindful when you fall sleep and it would be much easier to get your sleepiness over.
Eventhough the sutta says left side is for kāmabhogīs I do not understand why right side is much better than left side.
Normally, worldy things are considered left sided and supramundane things right. Our body is intrinsically trained to use left side, and left side is with more power than the right.
Hope someone can find scientific evidences may be??