a while ago i saw a thread on twitter along the lines of how there was supposedly another album recorded before ultraviolence and it would apparently include JFK, angels forever and the old version of black beauty. i don't know if i remember correctly but does anyone know if this was even true lol
Chris is just a mastering engineer, this is a very final step of the song's mixing and he only does final adjustments to prepare finished songs to deliver correct mixes as every service/media - iTunes, Streaming, CDs, Vinyls has different requirements. This isn't a step that any song that isn't meant to be released even goes through.