If someone’s up for it:
Seems like Midwest has created a bunch of skeeler routes:
No idea what the data license is.
Ruiselede has some GPX files on their site: Skeelerroutes Ruiselede - Gemeente Ruiselede
Seems to also be physically shown (similar to most walking/cycle networks using poles and badges on them). Atleast in Ruiselede.
All of these routes are on RouteYou and are maintained there by Sport Vlaanderen. You can download the gpx-files there. Link to group with all the routes —> Prov. West-Vlaanderen | RouteYou