We always prefer calls to come in as early as possible, where maybe an issue can be resolved with advice or a daylight shout to an warm, ambulatory casualty in mild distress. That will always be preferable to a long search for a casualty in possibly deteriorating weather, losing light, without comms, with the prospect of a rescue turning into a recovery.
Mobile phones may have greatly increased the number of SAR shouts worldwide, but also massively reduced shout lengths. Searching used to be the largest time sink in every shout, which is no longer the case.
Every SAR team has frivolous calls, but that's part of the game.