Enduro / Offroad Mode
In general, Kurviger supports riding over unpaved roads, as long as it is legal to use them, based on the road data. We don't have a mode that favors gravel roads, right now.
If you want to use a certain road that is legal to access, but Kurviger is not routing over this road, you can use the beeline mode (bird icon) to connect waypoints ignoring the road network. The beeline mode can be useful for road works, temporary closures and the likes as well.