I can second BS's post.
As something of a wandering police driver
I can confirm that Chiltern have developed a very sensible agreed process for handling mispers/MFHs with informed TFOs, which materially improves the hit-rate and avoids wasted flying time. It does require acceptance of their competence, by senior management. There are/were some other ASUs similarly placed, but a lot who are still forced to operate on the basis of requesting rank, rather than level of knowledge and viability of the search.
Perhaps this is one of the first areas where NPAS could actually benefit operational effectiveness, by adopting a similar nationwide approach?
[Not holding my breath though!]
Do remember though that there is another benefit of using the aircraft to clear an area. It saves on the use of scarce ground units. People who have not been involved would scarcely believe how many police resources are thrown at misper searches. They can sometimes denude a patch of almost all "bobbies on the beat" and similar for days at an end.