So is there any natural phenomenon that the FE model will predict with more accuracy than the RE model? Or are we just going to play word games all day?
There is no one phenomenon because RE explains away all features of existence as "illusions" and "tricks of the eye".
For example, FE predicts that when you look out your window you will see a flat earth extending farther than the eye can see. RE explains this away as an illusion, that the globe earth is, very conveniently, just large enough to create the perfect experience of living on a plane.
FE predicts that the earth is still and that the celestial bodies move around on their own accord. When we sit on our porch and look at the sun or moon move slowly across the sky on their own we do not observe the earth spinning. RE dogma would have us believe that this is yet another illusion; that the globe earth is spinning tremendously at speeds over a thousand miles an hour – faster than the speed of sound at the equator – despite us being unable to feel this centripetal acceleration.
When we walk off the edge of a chair and observe the surface of the earth, the earth is seen to accelerate upwards towards us. We do not observe a “bending of space-time” or mysterious sub-atomic particles which permeate all of existence attracting bodies through unexplained quantum effects. RE proponents would have us believe that our experience of an accelerating earth is an illusion, that instead the fabric of space-time is bending all around our bodies and accelerating us into the earth, despite a lack of evidence demonstrating so.
The earth is flat literally everywhere we go. Everything we do and every living experience we have is made on a Flat Earth. Not one single thing in human experience suggests that the earth is round. RE'ers conveniently explain that this is all an illusion, that our experiences since birth have been nothing more than one illusion after the next designed to create the perfect experience of living upon a flat earth despite being so ‘obviously’ round.