KOK dct DIK is very much a military concern during daytime, after all they have to have somewhere to play.
To some extent direct routings are also dependent on the mentality of the staff involved, some will do the extra co-ordination, some won't. There have been considerable improvements in ATC flexibility in the past few years as data exchange improves.
Invariably when a direct routing is available you will be offered it.
Older controllers at Maastricht may remember Swissair and "the chocolate route", KOK dct SPR - who said bribery doesn't work?
. But remember the co-ordination involved - Belgian and French military and at least two sectors at Reims - very complicated