@grammargirl
You might like this fascinating method where the developer of the Overcast podcast player worked out how to create individual sync’d transcripts for podcasts including those with dynamic ad insertion.

A little more than a minute starting at this link pretty much explains it. Some anti DAI ranting follows soon after that you might not want to hear 😏

Buying 48 Mac minis is also a very crazy story. The feature is only in beta so far.
https://overcast.fm/+ABQnv4MC0jU/2:02:45