Well, I did a check with the GPX-file from Cycling tourism: Via Romea (Francigena) cycle route - EuroVelo - EuroVelo and was a bit surprised:
There’s a gap between Luxembourg City and Schengen
The second french part is missing because of differences of the GPX-track and the routes, the GPX track doesn’t touch France but is completely in Germany:
Blue: GPX-track that I’ve downloaded, red the route as mapped in OSM and the tool.
Either it was an outdated gpx track or there’s work on the gpx tracks too.
Along the gpx track I found some other errors of the track too.