Enhancing the transcript schema

Curious if I'm just missing something on this or not, and if not, if
there's anyone interested in collaborating on improving it. What I'm
looking at is the transcript schema (https://schema.org/transcript). As it
is, it's wildly simple, just taking text.

I currently run a podcast and produce transcript content for it, and I'm
working on how to mark it up so that it is as accessible and useful as
possible, and in the process, it seemed like there should be a clear way to
identify things like:

   - Type of transcript (machine, human, or other)
   - Speakers of different parts
   - Parts of the transcript (intro, body, outro)
   - Language

Along with being able to add the transcript object as a property of the
podcastEpisode schema. Is this the kind of thing that just needs someone to
champion it?

MPF