I'm slowly realising that my colleagues for whom this "works" are never going to change. Our shared folders are littered with "Copy of FINAL final + comments 2.7.18-my-copy.docx.docx". It doesn't matter how slick my git + markdown + pandoc workflow is when conversations go like this:
"Just use track changes."
"But..."
"JUST USE TRACK CHANGES."
Comments might be extractable, I'm not familiar with docx format but it's zipped X(?)ML type data so there will be parsers. Or a conversion to an intermediate format that's more amenable to computer processing, perhaps.
The problem remains in reverse, though: it's expected that I will produce Word docs full of track changes edits.
Zotero's cross-platform plugins meant I could use any device for reading and not worry that if I followed important links I'd never find them again.