Mirror lenses and BIF?

Depends on what you deem acceptable, how "once in a lifetime" the shots you are using it for are.

I have 2 interesting 300mm lenses - the OM 300/4.5, which is a heavy piece of kit and probably really expensive in good condition. It is OK, but not outstanding.

The other interesting lens would probably be overlooked by many, it is a Sigma 100-300/4.5-6.7 DL plastic kit lens, sold with Pentax cameras. It is small, light and gives average image quality (though still usable) but of course, is dirt cheap.

None of these lenses are good for BIF, but are good for wildlife - one of the reasons I have them.