I've got red dots on Handis in .357 Maximum, .45LC and .445 Super Mag. I like em and don't like em. They're TruGlo and A1-Optic. They're larger MOA. They make it very difficult to shoot anywhere near MOA at 100 yards. They are excellent in low light. If I'm still hunting, jump shooting, I like them. Shots are close and come up quickly, and they find the target easily with both eyes open. They're plenty accurate enough for that. If I'm gonna sit in a blind or tree stand all day from dawn til dark, I take two rifles. One scoped and one with a red dot. The red dot for close in, dark thirty shots. The scoped rifle for longer daytime shots. I have a vision problem, and until I got the red dots, my hunting day was over at 4:30....couldn't see enough through the scope. The red dots added two hours for me, one in the morning and one in the evening.
The .445 isn't the thumper your .500 is, but it wears a TruGlo, and it hasn't wiggled yet. Because of brass and ammo scarsity, it hasn't had more than a couple of hundred .445 rounds through it. It has had hundreds of .44 mags.
This doesn't really answer your questions, but it gives you my experience with red dots.
Pete