Whilst not necessarily a NSEA 'expert' I am at least valid on the sector, so perhaps I can give some sort of help with the FLAS issue.
NSEA under NERC simply does not work without some form of FLAS. The problem is the crossover between UM604 and UY70/UL602/UL74 at BEENO/TOPPA. Because of the time parameters for electronic transfer of details between MAAS and London, there is insufficient warning of conflicts between UM604 westbound (i.e. southbound) traffic and UL602/UL74 traffic westbound. As in theory sectors 11 and 33 are separate (although we can't open them both together due insufficient staff!) and the boundary is only a few miles north of BEENO the problem is that 33 might have traffic which is OK for him at TOPPA but a ringer with something at BEENO and no level available to change it. So the use of a FLAS provides sorm form of initial separation at BEENO/TOPPA.
Having just done my farcical final OCT module, I can confidently inform you that the MAAS westbound FLAS levels are 260, 280, 300, 340 and 400, while Copenhagen can use 260, 320, 360, 380 and 400. Maastricht have moaned enough that they have been allowed to request the use of FL310 (an eastbound level under RVSM) at certain times of heavy demand. This screws up the eastbound traffic on five other sectors (Scottish, LUS, Clacton, 10 and 11) but hey, who cares!
I have a feeling that NSEA will be the fly in the ointment with regard to the NERC system, but we shall see... <img src="rolleyes.gif" border="0">