What sort of "adjustment" do you imagine would be necessary? Railways, bridges, etc. are constructed from short spans, for ease of construction and transportation, and to allow for thermal expansion. Suppose one of these spans is 100 feet long. It's easiest to build such a span perfectly straight, but you suppose it must "allow for the curvature" if the earth be a globe. So, do the math. If the earth is an 8,000-mile-diameter globe, then to perfectly follow the curvature, a 100-foot span would have to bulge a whopping 0.0007 inches in the middle (that's just about the width of a silk fiber). In other words, a series of STRAIGHT spans will do the job just fine, even without the silk-fiber bulge in the middle; they'll bend as necessary at the joints (by 0.0000043 degrees). Gravity does that work. No "adjustment" necessary.
When flat-earthers speak of "all visible evidence," what little they can actually produce seems to go into their eyes and then somehow completely bypasses their brains. They honestly seem to believe that "if it LOOKS flat, it MUST BE flat," and that literally no other analysis of the situation is necessary or possible. It seems like none of them can get to the concept of, "what do you do in case a large globe produces the same appearance as a flat earth? How do you distinguish between the two situations? What kind of math can you use to understand what you should expect to see?" They seem to be terrified and suspicious of math.
Their "visible evidence" isn't backed up by anything. They make pronouncements like, "the horizon always rises to eye level," and simply expect people to believe it. But this claim is contradicted by centuries of experiments -- EASY experiments, that flat-earthers themselves can do, but they REFUSE to do them. Experiments CLEARLY show that the horizon dips down by an angle consistent with an 8000-mile-diameter globe. This was done as early as 990 AD by astronomer Abu al Biruni, who used a simple astrolabe to measure the dip. You can also measure it using a good theodolite, or a special prism that attaches to a sextant, designed for just this purpose. Or see the May, 1979 issue of Scientific American magazine, which describes a clever technique that requires only a ruler and a piece of string; the article also discusses some actual experimental results. Or see Timothy Smith's YouTube video, "The Size of The Earth", where he demonstrates a similar technique. The point is, the flat-earther claim that the dip angle is "zero" is a flat lie.
If the earth were flat, we should be able to see Hawaii from Los Angeles (it subtends an angle 4 times the size of the full moon). Flat-earthers counter that "atmospheric haze" makes that impossible; yet you can clearly see the moon itself on the Pacific Ocean horizon (through all that atmospheric haze). Other flat-earthers simply make up fairy-tale rules of optics and geometry, and claim that Hawaii lies beyond a magical boundary called "the vanishing point" that no one in the real world can explain.
The positions of the stars are different as seen simultaneously by two observers in different places. If you "shift" one observer to the other's position on a flat earth with a nearby firmament, the change in the stars looks a certain, predictable way (predictable by geometry and trig). But if you "tilt" one observer to the other's position on a globe earth with very distant stars, the change looks a certain DIFFERENT predictable way.
The way it ACTUALLY looks, is the "tilted" way, not the "shifted" way. There is simply no way the view of the sky we see could be produced by observations on a flat earth. It is geometrically impossible.