Most I shot in a day was about 270ish for 1 day.
What issues have you seen with optics for these courses?
I've seen issues with a variety of optics. Including optics from mfrs with reputation for high quality and robust products. My point was more to get your context, which I had a$$umed and that you're "gtg".
To answer your question, I've seen:
1) Trijicon 1-4 that was fine at 1x, but way off at 200 yards at 4x. Was during a class, so the owner didn't have much time to iron it out.
2) Aimpoint T-1. Elevation dial didn't work. I ended up loaning the T-1 on a second rifle I had with me.
3) Aimpoint M2. Don't recall what the issue was, but I ended up loaning the T-1 noted above (second day of the class).
4) EoTech. Forget which model, but the lens was loose in the housing. Rendered the optic useless.
5) Holosuns. Have seen a number unable to hold zero, but not sure if it was the optic or the mount. I've seen many Holosun mounts work their way loose, but no idea if the owner used loctite or proper torque.