How much support does it have for geodetic engineering? I’d love to be able to use more FOSS Software in this proprietary dominated work field :)

I’ve driven the same general route a few times and even then, it has been quite reliable. As mentioned, it can depend on the cities and stuff, so you’re best trying it out for yourself :)

I’d like to recommend ‘Magic Earth’ to everyone, who wants a privacy respecting Maps alternative with trafic data. I used it on several >500km trips and it only misguided me once. It uses OSM maps and can navigate offline.