Have to admit Birmingham was a surprise given their presence at EMA buT lba clearly does not have the space for a say a 4/6 ac base DSA does! LBA is struggling with terminal capacity now and will do for the next 2 years DSA is not. LBA owners will be very cautious of welcoming Ryanair with Jet2 being their main source of income at the moment.
Remember Ryanair increasing their daily DUB flights until the startup deal expired they moved the extra flights to MAN when a further deal was denied. Granted thery are back at 3 daily now. Ryanair will, I feel get a deal at DSA and when it doesn't work out look at LBA in say a year or so when the infrastructure has started to improve.
Just my thoughts.