Staying still is just a suggestion, it works for some people.

Personally i've never found staying completely still works for a WILD, i always get to uncomfortable. It feels unnatural. So i try and move as little as i need to, just enough to remain comfortable. I'll sprawl, roll over, whatever it takes to feel relaxed and able to sleep again.

Just use common sense, all you are doing with a WILD is trying to fall asleep. For some people moving slightly will keep them awake, for some people staying still to the point where they are uncomfortable will also keep them awake (like me and apparently you too)

Just relax, let yourself fall into sleep.
Don't take the suggestions of forums as gospel, they are just suggestions. Use your own common sense and understanding of how you sleep and come up with what works best for you.