I'm pleased the idea of zoning is seen to have some merit. On further thought the zones could be geographically limited and time separated on a set rota.
Certainly this would be disliked where the weather or activity require a different time/zone but that is what its all about. Even in a war zone it is never freeplay.
Lincolnshire could, for instance, be low flying 09-12 whereas the counties en route from the helo base could be 06-09 so all helicopters fly out in one zone and the switch to another helicopter zone. Somat like that anyway but such details would be well above my pay grade and away from my experience.
Regarding height estimation, this week we had the 'correct' identification of the potential offender and the complainant, an air traffic controller and the crew all stated that the height was 250 feet. Was this a first?