NLN, thanks for addressing my questions.
I had in mind particularly that if Luton got two runways and there were any attempt to use them to capacity, would that mean (a) dedicated stacks where there are none now, so more CAS at FL 55 or lower within range of Luton, and (b) maybe also more for Stansted, NE of the latter, to get all their traffic away from Luton/shared stacks?