BFS-BRU ?
Personally, I'd like to see the addition of BFS-BRU and I'm surprised that thus far it's only LGW from the UK that ops to/from BRU. I say "personally" for purely selfish reasons only because I live/work in Maastricht in The Netherlands and BRU is handier by far as opposed to the trek up north to AMS.
However, I would've thought that there would be sufficient demand from the regional capitals BFS, EDI & CWL (..although ops ex BRS of course) to warrant even a daily service given the politics and the direct relationship between those individual regions and the European institutions based in BRU.