Draw a curve and place your scopes on it like was mentioned with the bridge and towers and show me how those two scope crosshairs can be seen pinpoint to pinpoint.
The bridge argument kills off the scope view.
Ok
Before you start, the Earth in blue
is curved, but it's so big it just looks flat.
The line between the two towers represents your scopes, looking at each other. Even though the two towers are actually leaning very slightly away from each other, the angle is so tiny that the scopes will still be well within each others field of view.
I know you dont like/understand field of view but it's still a fact.
I know you're expecting the two scopes to be pointing up in relation to each other and therefore missing from each others crosshair, and if the bridge towers were far enough apart this could be the case, but firstly that would be one hell of a bridge and secondly, there is no reason why the scopes couldnot be angled to compensate, unless the towers were so farapart that the curvature of the Earth hid the scopes from each other of course, but again, that's one hell of a bridge.
Oh and....
The higher the viewpoint, the further along the curved surface you can see. Unless for some unknown reason you are not allowed to move your eyes or neck and only have single pixel, pinpoint vision.
I know you dont do scale, and I know that on this diagram the eye is moving 100s of miles above the surface, but the geometry works the same on any scale.
See 13080 if you need more accurate numbers