Perhaps the solution to all this cross border thing is to take the Scottish route to a single, countrywide, Police Force.
From next year, all the people of Scotland will be served by a Police service which has air support. No borders no problems.
No more assets though, so the travel time to most jobs in Aberdeen will make it unworkable, but the local polis will (on paper) have a helicopter, even in the Highlands & Islands.
The fact that it will STILL be in Weegietown makes things difficult, but at least the force boundary issue will have been resolved.