Hi again Paul,
I've tried out all the plugins you've listed, though not with learners yet, and everything works smoothly, logically and easily. I actually think it's an improvement on the Nanogong plugins because #1 - The audio is transcoded to MP3 so it's easier to incorporate into other activities and uses the standard Moodle audio embed features, #2 - avoids the issues with JRE versions, blocking, etc.
As you may well know, peer review writing has been gaining popularity for both first and second language writing courses over the past couple of decades, and the research on its efficacy is encouraging. A request I've had from some teachers and curriculum developers is to be able to do the same with audio recordings.
One thing I'd like to suggest, which isn't in the Nanogong plugins either, is a dedicated peer review audio assignment type. Yes, you can use the existing peer review assignment type and ask learners to embed their audio submissions using the WYSIWYG editor, but that means teaching the learners how to do it (and providing a lot of extra technical support for both learners and teachers) rather than it just being set up and working logically and easily for them.
Does that sound like a good idea?
Thanks for all your hard work and dedication and contributing a great plugin.