1. Idealized? No, you're saying math is wrong. Where is the disclaimer by ANY globe-defending organization that those earth curvature calculations are "ideal"? Where does any mainstream scientist deny the curvature drop given by those calculations?
2. Mirages are mirages. They aren't MAGIC like some kind of magic wand or photoshop tool, to magically erase the earth's curvature or bulge, bringing entire city skylines up a hundred miles around the "curved" earth, making them appear perfectly straight up, with no waviness or distortion. Sorry, I'm not buying the crap you're selling. There are no "Refraction Fairies" that magically make the globe earth appear EXACTLY as if it were flat. Give me a break.
3. "All distant objects", "all the time". How about we start with ONE bit of evidence for this. Nothing from NASA though, for they are proven liars. One of the reasons Globe Earth can't be true. Why would NASA lie so much and go through so much time/effort/expense to deceive us, if all they had to do was take real, honest pictures and tell the truth?
So this is all about the "we shouldn't see this thing" argument.
Every single time this is used, it's about objects that are suspiciously close, so the numbers are easy to fudge, and they're always above water, so you can talk about refractive effects to convince people that don't know how refraction works.
I challenge you (the FE community) to show something over land that is far away, say 1,000 miles. You can use binoculars, telescopes, whatever you want.
Same goes for the boats that disappear out of view. You can zoom in all you want, they keep disappearing bottom up. Demonstratably, all the time, everywhere. And this is over water, with all kinds of reflections and refractions by air layers going on.