For what its worth, I keep a D reg Rheims Rocket here in EGSN, Go back to EDLN every year for annual.
So route via Southend Ramsgate to Konan (intersect point of 3 boundries) the FIR boundry to Brussels FIR to Kokside EBFN (talk to Ostende Approach 120.6) then decend to 2000' to Ursel EBUL (talk to Brussels info 126.9 and request transit EBUL) to route between Antwerp and Brussels at 1200' over Mechelen (Heliport EBMW)as a marker to BUN vor then request from Dutch Milatery for climb to 2500' on up past the north eastern side of Kleine-Brogel zone round the top of EHBD Budel zone on into Germany switching to Lagen Radar 128.5)
This is only my normal routing but I do not say in a definitive sense (legalese. Only a serving suggestion)