Thanks for your links! They helped a lot! I decided to purchase the Asset yesterday because of your dedicated support!
By now i managed to download some tiles and load them into Online Maps via Resources. The offline-loading works really nice!
For the navigation part - i had a look at the navmesh example that you posted. Unfortunatly, it seems to generate the navmesh "on the fly" - i would need a pre-built navmesh (a 3d gameobject) to work, because (as far as i know) i cant generate a road-navmesh based on the tiles texture. Also, the navmesh should be extending the borders of the view, because the user must be able to navigate to a location that he is not seeing at the moment on the map). I thought about pre-modelling the navmesh and then, attaching it to the map like a 3d marker.
I already managed to attach a 3D marker, but unfortunatly (in my use-case) the marker disappears as soon as he is out of sight. that makes sense for markers of course, but not if i need it to stay for pathfinding . do you have a suggestion how to tackle this issue? deactivating the "SetActive(false)" in CustomMarkerEngine.cs line 92 didnt do the trick. it would be nice if we could find a solution to this, as manually placing lat/long nodes on every street seems extremely daunting to me - simply modeling the streets would be a LOT faster....
Thanks a lot for your help!
PS: Also, i would need to figure out how to scale the marker with zoom level accordingly, but that should be doable with some specific ratio i guess...