Everyone who cares about AR/VR design should read this locomotion research from Oculus Research
Still sick with the flu, so not ready to write more about AR locomotion issues. But here is a good starter set for anyone interested in the subject. Oculus Research Into Comfortable Locomotion and also this video Solving for Locomotion in VR I'm going to try some of these with low end device Camera-based AR, as a demo, to see if they make any difference. And I think I'll also try them with Cardboard with or without an AR backboard. I think it's easy to say that inside-out tracking and especially hand tracking are also high on the list for dealing with locomotion, but the above might help immensely with the nausea issues that both VR and AR (with camera lag) have.