Conformance of Synchronised Lecture recording transcripts

I wonder if anyone can help.

At UCL we're keen to follow WCAG 2.1 guidelines regarding access for pre-recorded video. We, like many other educational institutions, are now generating thousands of lecture recordings every year.
Our Lecture recording provider facilitate transcriptions (first pass using an automatic transcription engine the output of which can be subsequently corrected in an online editor).
The output of the transcription is a .vtt file containing timing information and the interface provided allows the transcript to be viewed alongside the video. The transcript scrolls automatically, highlights the section being spoken and also allows text searches of the entire lecture. The transcript also allows navigation of the video as clicking on any text in it synchronises the associated video to that point. It would seem to have some distinct advantages over captions.

I've been searching the guidelines (the closest I've found is - https://www..w3.org/TR/WCAG21/#captions-prerecorded)  for something that would allow me to be confident that this kind of facility complies with WCAG2.1 guidelines and also to understand what level (A, AA, AAA) could be ascribed to it but can't seem to find a mention of synchronised transcripts - Should I be looking elsewhere ? - any suggestions would be gratefully received.

Regards

Rod Digges
Digital Education
University College London