mp4 ingest clips with non-stereo audio is broken
With all the new wizz-bang tools coming out to help use collaborate online as editors, there is a need for a lightweight proxy codec tuned for speedy streaming and quick transfers. H.264 is perfect for this as you can set the bitrate very low and get a very sensible SD Wide Proxy at something like ~2Mbps.
The problem is that Premiere chokes on generating proxies for anything with more than two audio channels. I have not yet found a workaround.
This works fine in Resolve, Handbrake, etc. I wish it worked in Premiere as well.