So let’s summarise all of this. Longitude, even measured in degrees, is not a problem for the FE system. However, regarding latitude:
1. Star trails are observable, and can be seen both in the South and the North. The centre of the northern star trail is Polaris, the centre of the southern one is Sigma Octantis. I am ruling out faked pictures here because star trails are in principle observable by FEers.
2. The only explanation of star trails consistent with FE is a geocentric system where the whole universe (sun, planets, stars) has an axis of rotation drawn (in a straight line) from Sigma Octantis to Polaris.
3. This straight line, i.e. the axis of rotation appears to change its angle depending on our position north or south. Only at the equator is it parallel to Flat Earth.
4. Either the axis actually changes its position, i.e. moves, as the observer moves north or south, or it does not move, and the flat earth is not flat.
This is a conclusion based only on observations that FEers agree with, and cannot be faked, and with a bit of logic (not much).