Flown quite a few times through Belgium VFR, we always choose a route which avoids controlled airspace although this can be difficult as there is so much of it (plus restricted areas in the east). It took us literally hours to pick a route through avoiding all airspace reservations, and in fact we realised only after the first few times that our route actually went through the Beauvechain TMA (luckily it is weekday only, and our first flights were at weekends!).
Brussels Information and Belga Radar very helpful, the latter giving transit clearance of Beauvechain TMA on a weekday. You can request Belgian NOTAMS by fax by calling +3222062530.
Do let us know how you get on.