And finally, I succeeded in pushing the latest version of VR3 to Leo's devel branch.
Thanks so much to Matt and everyone who helped get this straightened out.
The main changes to VR3 were to correctly find executables like asciidoc3 that were not getting found on Windows. It turns out that asciidoc3 gets installed into a Scripts directory on Windows but not Linux. The new code can find this location whether or not you are running in a virtual environment. In addition, the RsT fallback plain text rendering when docutils is not available now works. Of course it doesn't look that great since docutils isn't rendering it, but at least it displays as it was supposed to.