I just checked, both EBD26 and EBD29 are training areas for our F16 interceptors. Both are active per NOTAM only, and both are limited to 4500 AMSL.
I can't speak from experience, as my craft is not allowed in controlled airspace, but I think one does not negotiate routing with ATC. One plans the flight, and files accordingly, and if they don't like what you are doing they will tell you. Better to plane carefully, though.
Stay well away from EBFS Florennes, it is one of our two bases for stand-by interceptors. They are only scrambled a few times in most years, though, or even not at all.
And be aware of the possible activation of some class G airspace above 4500 AMSL, but this is done for the benefit of gliders and will rarely happen midweek, except during holiday periods like July-August.