This image explains the problem Tom is having nicely:
The bright light from streetlights on the left of the image are actually getting a little smaller with distance - but (as Tom loves to assert) they aren't shrinking as fast as perspective would suggest.
However, there is no "magnification" going on - because if there were, the signs in the distance would be just as large and legible as the ones nearby - and we ALL know that doesn't happen.
This picture shows this even better. The bright, far distant SIGNS are not getting bigger. They are getting blurrier - but NOT bigger.
What's happening is this:
Light from the streetlight (the yellow circle) shines outwards in all directions (the red lines) - but when the air is misty (which is always is to some degree), the light rays hit water droplets (blue dots) and are scattered off in all directions (the green arrows). This is called "Mie Scattering":
https://en.wikipedia.org/wiki/Mie_scattering - and it's a well documented and understood phenomenon. No FET magic required.
The secondary light reflected from those droplets forms the glow that you see around the lights. So our eyes (or a camera) are gathering light coming directly from the light source AND light scattered from water droplets closer to our eyes.
The further you are from the light, the more droplets there are between you and the light that can scatter it back towards you - so the glow AROUND the light tends to fight the effects of perspective (not 100% - but certainly to some degree). However, the DIRECT light from the source itself stays exactly as the ordinary laws of perspective say they should.
This is why the neon signs in these photos get blurrier - but they DON'T get bigger. You can't read a neon sign that's 20 miles away - even though it's glow may be huge.
If RET is correct, then the sun remains the same size between zenith and sunset because it's distance remains the same.
If FET was correct then the disk of the sun would be about half the size at sunset (because it's further away) - but the effects of Mie scatter would produce a glow around the sun which might well be larger than the sun at zenith.
HOWEVER that's not what we see. The sun doesn't get fuzzier at sunset - it forms a perfect disk with a relatively sharp edge that's the same size as the disk of the sun at zenith.
So, sorry Tom - the "magnification" theory is doomed. You can't read neon signs from 20 miles away - so your theory is WRONG.
You have no valid explanation for why the FET sun doesn't halve in size when it sets.