Skyrim's map is static, it doesn't animate the player moving, plus that map was created by a team of triple a game developers. I think theres a reason sesoms map is like it is.
***Granted: Difficult for modders, (which was your point). I absently was thinking about developers with the source code.
Even so...for a mod there could be a level like Sesom's, but with a terrain map, and a custom creature (or outfit if need be) for a map marker. I was thinking akin to the tumble weeds in New Vegas that float along the ground. Unlike Skyrim, a Fallout map would have settlements few and far between; uncrowded, and not requiring pin-point accuracy to select.
The tricky bit might be allowing for en-route random encounters that necessarily spawn the PC at a mid-way point, and choosing the correct terrain/location based from the PC's position on the map.
Alternatively: The map could be entirely a menu, with use of the mouse, and not a loaded level at all. It doesn't actually need to rotate around under player control. It could be as simple as moving a 2d picture of a 3d landscape; or more complicated by making the map transitions into 3d animations of the menu asset. If need be, the destination selection could be done just with labeled buttons; and no point & click—though that would certainly lessen the experience. A part of the fun was exploring revealed tiles as they meander around the map.
Of course, it's only speculation on my part; I haven't touched the game (or editor) in years. I had hoped that picking them up during GoG sale would spark renewed interest in modding it once more... but it hasn't yet.
I have just always been disappointed that they did not implement this officially in FO3 from the outset.