Yeah that's what I do (STT -> LLM -> timestamps to block), but if you did that for every episode download, due to location-targeted dynamic ads, your LLM API bill would run up very fast. So that's where the fingerprints matching comes in, for further versions of an episode (version = same episode but with different dynamic ads inside).
I explained how the full system works here (someone emailed me and asked): https://pastebin.com/raw/r2YUEkK5