Im amazed that the CAA are going to allow this to go through, it certainly does not encourage the use of the flight plan and SARTIME system.
I say if you file a SARTIME now, get your moneys worth and make the poor CH INFO controller earn the 0900 with position reports every 5 miles. Im pretty sure the 0900 will disapear when nobody can get through to them for the 5000 position reports going on...
Whilst cancelling in the air is an option, it would be an awful shame to cancel a few miles out and then be unfortunate enough to need the SARTIME....
and as a ATO there must be a flight plan for the entire flight....cancelling in the air wouldnt meet that requirement.....