As it is, PluralEyes is not perfect and gets a little dodgy on occasion. It can work very well with a really good reference track, and I usually do this by sending the camera a wireless hop of the mono mix.
I also think for doco situations -- and by that, I mean "getting shot at in Afghanistan" or "running down the banks of the Amazon" -- slapping a Sennheiser 416 on top is understandable, assuming you're just getting B-roll footage. But again, it's not going to work well with actors' dialog or reporter's commentary.
It does amaze me that people are trying to use a $100 microphone with a $40,000 camera.