My initial feeling is that this is a subset of Popcorn.js's functionality. (I haven't ever used Popcorn.js, though.) Is that correct?
Correct, this looks like a less capable Popcorn.js
I have discovered popcornjs just 2 days ago and yes, presentz seems to me too a less capable popcornjs.
they grew independently and do things differently.
It would be nice to see presentz.js plugins merged into popcornjs
that sounds interesting, I'll give it a try! Do you know if it's possible to export it as a standalone html+js page? I'm not sure there are any better solution, incrusting the slides directly in the video is too much for a webapp ...