Andrea,
This site, with a good overview of CAI in BoB,
only mentions Chiévres and Melsbroek are CAI bases.
http://surfcity.kund.dalnet.se/falco_bob.htm
I think that good compromisse for CAI Campain is France base in Zutker... (0-11 grid, is inland base, flying distance similar to Bengiun ones) as "Belgiun base", with first leg of fly do Nort, and over sea change for apropriated course.
Sokol1