So I found this topic, which weirdly I am unable to respond to:
https://www.keyshot.com/forum/index.php?topic=21103.msg89548#msg89548
Since I can't respond, I did want to update everyone that this solution no longer works. It produces a nice .mov file that plays in VLC perfectly, but it will not import into Premiere Pro CC anymore, as Adobe "updated" premiere and it no longer supports this codec. Rad.
I also tried all the fixes mentioned on the internet, renaming .mov to .mp4, converting it (lose transparency), etc. No dice. So thanks Adobe, for fucking people over who want an easy way to composite. Now we need to export frames and import them as batches, which is annoying.
While that may be true, 99% of people rendering video for animation rely on frames output. There are lots of benefits to doing so, despite the extra steps it takes to composite them.
wait what? oh noes, I just shared with 30 users in our two companies that you can use mov for alpha channel, :cries:
okay back to PNG sequences.