Totes, gotta hand it to you, you're right hitting all my favorite topics here. Also,
I couldn't resist, since nobody has done it yet.
Eh, I'm not crazy for the gears myself, but I understand [the need for
something like] it. There is a youtuber called
p-brane who
recently did a video about this, but I don't think he satisfactorily summed it up. He tries to demonstrate the 'diamond' shaped red lines depicted in the above image, as the 'lense' perspective we are familiar with from the ground; IE, in particular, crepuscular and anti-crepuscular rays convergence point
during sunset; which looks like 2 suns; the real one and it's opposite on the 180 degree opposite horizon (forming giant 'diamonds' in the sky). Of course, sundogs also exist which can be a useful tool in understanding 'flat earth celestial functions', but I'm still at a loss to bring it all together. I mention it simply because it is one avenue that isn't mentioned often.
Of course if you google 'sundogs' you are gonna get a load of "Nibiru" conspiracies. So do that at your own discretion. It is also interesting, that you cannot see a rainbow indoors, without the use of a mirror. It has been postulated that something in the atmosphere (ie flat earth dome) is acting like a mirror, enabling 'free rainbows' which shouldn't exist without a giant mirror somewhere overhead.
But like I said... I'm not tying all that together. The FE model isn't complete so far as I'm aware on this one topic you have presented here, that is obvious to anyone who spends a few days researching it. The devil, as they say, is in the details. And this one is still eluding me. Sorry for rambling but that's my $.02. Hopefully this is a little bit better
post quality than what I started here with; I like to think I understand these topics a bit better now, thanks in no small part to correspondence here.