Done. There is now an orphan branch "spec-full" in the upstream repo whose only contents is an AsciiDoc document of the complete spec, with all includes processed.
The first commit of that branch represents the spec after the conversion to AsciiDoc, i.e. it contains no actual content changes over BV 1.1. Comparing HEAD from this branch to the first commit of this branch shows the changes done in BV 2.0.