When playing on 3440x1440 with large GUI size, the locomotive HUD disappears. By resizing the window, you can find it, but by default it is hidden and I don't see any way to move it around.

Could the mod automatically detect the window resolution and place it accordingly? It seems to be putting it at a certain absolute position (without taking a look at the actual code, that is...).

Yeah I noticed this during many many test that we are best compatible with 16:9 resolutions. I will look into the code how we place the thing.