I’m unable to reproduce the issue. When I add a fuel station while in navigation mode, Kurviger treats it as a regular via point. For example, in the screenshot, waypoints 3 and 7 are fuel stations. I can skip them simply by selecting a later waypoint on the route.
It’s possible there’s a misunderstanding: Kurviger doesn’t let you select what to skip, but rather where you want to skip to.
If you accidentally added a fuel station and want to remove it, you can do so by pausing navigation, tapping the fuel station on the map, and then deleting it.