I feel that for DILD you should be as comfortable as possable.

What about WILD? I will break it down into two types of WILD. 1st) The type where you intend to rapidly fall asleep, and stay mildly aware for a short time, hoping to enter into REM quickly. This is maybe the type more people use. In that case I suggest just being reasonably comfy. 2nd) This type is a self hypnotic trance state. You actually want to maintain a fairly high degree of awareness while totally asleep. You may need to wait for REM, and want to stay aware, while asleep for as long as it takes. In that type of WILD I recommend a position that is comfortable, but does not allow you to sleep as easily and limits your movement. In that case I use sleeping on my back with pillows to limit my ability to turn. If I hit awareness in deep sleep, and then feel some bodily discomfort, I may move to a normal sleep position, because I am already in the trance state.