I still concluded that an intended entrance/exit plan would still put searchers within a mile of where most 'wanderers' would be found.
A couple counter points, Bee. Solo explorers might typically wander only a mile from a trail, but there are many peaks, gullies, and other formations along most trails. So a good itinerary may constrain the search within a 2-mile corridor (1-mile either way), but it could still be many square miles to search. And there's still a chance that a major route deviation occurred. A transmitter sending location data regularly would narrow it down very precisely. However, in the case of a sudden lethal fall, a PLB wouldn't help if the hiker isn't able to operate it.
