Open Source Twitch Documentation
Twitch has one of the most intelligent and tech savvy user bases of any product I can think of. If Twitch were to make their documentation source code Open Source, members of the community that are tech savvy enough will do your job for you.
I just went through the documentation when trying to figure out how to make my first banner and my first Video Player Banner. I am unaware of what a "Video Player Banner" as someone that does not normally watch much Twitch but is attempting to start to learn more about it.
As someone that works in Open Source and helps with our OS Community management, the first thing I did when I saw it was bad documentation was see if I could contribute to it. If so, I would spend my time learning exactly what it is I'm missing and fix it myself. Your team only needs to take my code contribution. With the user base Twitch has and the creativity of it's creators, Twitch should have the best user experience available in every aspect because they can simply Open Source it to their amazing, very active community.
I would be happy to help talk about how I (as a legitimate tech professional) would implement this. I think it'd be a HUGE improvement on your processes and follow Conway's Law. Allow your users to design your processes and your users will fall in love with your processes. Twitch, with it's popularity, only needs to curate and run the servers.