IMO if it hasn't been mentioned yet.
Add a roll of survey tape to the list for ea. pack.
Then instruct ea. user if lost or hurt to tie one end of the tape to a tree/branch/rock/object then string out the entire roll of tape in a straight line accross a terrain feature then sit down and wait. Many times searchers will walk very close to someone without seeing them because the victim was asleep/ scared/ or hurt . The tape works 24/7 and someone
will bump into 150ft. of tape at some point if they are lookiing anywhere near your area. If you use silver mylar garden tape they might even be able to see it flashing from the air.

What I am suggesting by saying string it out accross a terrain feature is to lay the tape at right angles to any natrual direction of travel. I.E. accross a trail or start at waters edge and string the tape directly away from the shore line. Do not parallel a trail or water flow. <><