I'm still confused. You can't use polaris as a reference for positionning as its light is also bended at an unknown rate.
Doesn't matter. It's its perceived location that's used for positioning, regardless of where Polaris might really be.
Correct. And it is the perceived position that aligns with the lines of latitude, not its actual position. I don't have to know the rate of light's curve to determine the perceived position of an object; I only have to look at it. Knowing the actual position of Polaris wouldn't help at all in this case.
As I understand, you agree with RE distance measurements, do you ?
To sum up
I open my window, I see a flat portion of earth, this is compelling evidence of a flat earth.
I open my windows, look at polaris, but in fact, it's an illusion, still matching perfectly a spherical geometry. The real location is unknown, but for sure, it's not at the place it seems to be.
Doesn't matter, as the affecting phenomenon is absolutely invariable and predictable, even if -so far- no mathematical function can describe it.
You still haven't answered to my question. How do you really know the distance from your house to equator ? How did you calculate the sun's distance from your house?