Are you sure you don't work in ATC Shed? Because you have explained the absolute nightmare of multiple airports going into CATIII simultaneously perfectly.
And as for the Beluga, it's only an A300.
Also stating you will accept emergencies in a NOTAM is pointless, as doing otherwise is illegal.
I don't work in the UK, but if SNN, ORK, DUB, NOC, KIR or even BHD and particularly BFS refused to accept diversions EVERY YEAR, because they are using remote stands for car parking.... we would be absolutely livid over here. Eventually some commander is going to div into MAN and stop on the runway, because there's nowhere to park his aircraft