Oh, I'm happy to admit I'm wrong, I'm just not going to do it for no reason. The most extreme conclusion Thork could get from this line of reasoning is "Physics isn't complete," which no one denies.
How come "Physics isn't complete," is an acceptable answer for round-earthers but any unknown variable in flat-earth science is clear and irrefutable proof that the flat-earth theory is totally wrong in all facets and forms imaginable?
Because there's a difference between an as yet unfilled gap, and a contradiction.
The number of things that occur in the Sun (extreme heat, predominantly plasma, fluidity, wild magnetic field...) mean there are a lot of things that can and do explain the supposed problem: and even if there weren't proposed explanations, the comparison to the Earth would still fall for that very reason.
Whereas if you look at proprosed problems with FET you have, for example, sunsets: and I'm
not saying that's a good argument, I'm purposefully choosing a less convincing one, but if it was in fact true that under FET the sunsets we observe would not occur, that is a contradiction: that is not a gap waiting to be filled.
There is a huge difference between "Unknown," and "Untrue." Asking after the outside of the ice wall, the formation of the flat Earth, maps, etc: those are questions that target unknowns. Even with no answer, it doesn't render FET untrue, merely incomplete.
A contradiction for RET would be, for example, measuring a distance far shorter than what should be the case on a sphere, or a photo showing that the Sun is indeed a spotlight, or looking over the horizon with a telescope. Those things would contradict RET, and certainly they could be explained, it's just a matter of whether it's explained within the knowledge we already have, or if it needs more to be supposed.