The main use IMHO for outdoor camping or survival would be to locate vital kit in the dark. In case of an intruder, a beta light attached to a firearm or knife would enable you to quickly and silently locate the weapon without showing a light and making yourself a target.
(attach the beta light in some non permanent way such as blu tack or a rubber band)

In the home, beta lights can usefully be attached to door frames, and near stairs. The odd "reference point" thus provided allows safe movement in the dark.

Beta lights attached to light switches are useful especially for battery operated lights that might be needed in total darkness.