I think the ideas everyone has would all be remedied by simply making the custom dispatch area actually custom and not just selective..... big difference.
Choosing which circles of an area to cover = selective
Using a function already present in the game as a patrol route creation engine and the inside area being the coverage area, THAT would be custom = Everyone happy
This is exactly what I'm thinking of. Having the ability to 'draw' a polygon in which missions for certain stations or even dispatch centers would be generated. Just have a preset minimum area that can be drawn to meet to anti-cheat.