I've had this on my back burner! Glad to see someone else wants this as well. The Internet Archive already has transcripts generated by whisper.cpp, so it's (just) a matter of gathering them into one place and making a good search feature.

Example transcript (JSON): https://archive.org/download/episode_1109/episode_1109_whisp...

Screenshot from a month ago: https://wonger.dev/assets/chronicles-screenshot.png

I can reach out to their project to see if they're interested.