Well it would be nice if that was the end of it
I suspect though now that you have highlighted the safety sense that someone will disagree with it and it will be changed. I presume its had more pilot input than ATC input. And as NATS policy is not to do it, it would appear to be in conflict with both Scottish and London info.
But.......... before you change it.
How about thinking about an easy process to change to. The helpdesk has already had the number of bods on it reduced. And getting flight plans sorted should be the priority.
How about getting a mobile number either sim card or through skype and then pilots could just text the aircraft reg to that number to close the plan. Saves loading the phone line up and someone to answer it. Its quick and easy to see at a glance if someone has closed it or not if the updating the system is behind. Or for that matter aircraft reg open to open it and reg closed to close it. Saves all the buggering around by the various units trying to find it when they get asked to open it on a free call.
Just a suggestion!!!