While it seems YouTube's auto-generated are hit or miss, I wonder if feeding them through an LLM can fix the mistakes and still get the video's idea out of them
I've found that to be the case. I typically don't want a full transcript -- I want the materials list, or a summary, or a counterargument. I've found it is totally sufficient to just plop the transcript into an LLM and ask for my desired output. No need to clean of the transcript ahead of time.