"Back in the Day" (<--- my tagline again) I owned a plow truck that only ran in wet, usually salty conditions. Merciless rust was an unavoidable part of its life and eventual death. Factory bleed nipples had a cruelly narrow hex so that with far less torque than it would've taken to crack them they'd round over instead and it was game on for the screw removal challenge. I cured it by making my own bleeders with comfortably long hexes. That's one of mine on top, made of 304 stainless steel of course:
A really close stab at a successful bleed can be done on a cylinder with a broken nipple by cracking the flare nut and compressing both pistons toward each other with a C-clamp. The only air remaining inside will be the small volume between the tube entrance and bleeder socket. It wouldn't work quite as well for a cylinder installed upside down as it appears in Rob's photo but I prefer to think that was just a matter of camera access.
Every brake rotor or drum I mount, whether new or used, has four drilled and tapped jack screw holes whether I have to add two or do all four. It's the quickest, easiest mod that saves untold pain upon removal.