[Joe Roberts]

I did some experiments and tried converting some DNG clips into DNxHD MXF through Media Encoder. Unfortunately there was no way to keep it at 12 bits (10 bit maximum), and despite that, if I maintained 4:4:4 colour then the file sizes came out noticeably larger. If I lowered it to 4:2:2, they came out at about half the file size of the DNGs.

At this point it feels like I may as well hold out for Blackmagic RAW. It sounds like it will hopefully be a magic bullet for this kind of problem.