...the concave Earth theory is silly...
so it is silly, I agree. It doesn't mean I shouldn't look into it. And to my understanding I did show what is wrong with the convex earth theory. Telescopes and horizons. The ship disappears fully behind the horizon but when you zoom in with a telescope you can still see it. And don't tell me that it is a mirage due to refraction caused by the hot air above and cold air below. The "refraction" and "mirage" straw is way overused to "debunk" conspiracy theories. It's as stupid as a guard hearing some strange noise in Oblivion and saying "these damn rats again" or "it was probably wind". No it is not wind and it is not rats! It's a fucking thief stealing shit from the castle!
The experiment was flawed by construction. With our current material science knowledge, it is impossible to create a structure of any kind that will be straight over the distances required. If you think it can be done, you could make a lot of money. I would not know how to do it, and I am really not tempted to try. Also, I think all the information we need to falsify the concave Earth theory is already out there, despite what you have been claiming.
Did you just suck that out from your thumb? When constructing those straight bars needed for the rectilineator you would make them all from the same template. However, when finally using the bars you would turn one's face downwards and the next bar's face upwards. By doing so you would reset any error in the template that would otherwise cause the drawn line to bend in either direction.