There's a new version of vDosxy, which incorporates the changes to the revised vDos released a few weeks ago.
This version appears to be somewhat faster -- paging continuously (next or previous page command) through a long document looks to be snappier. According to the documentation, this version could be used with other programs: the "full INT9 kyboard emulation is now only enabled if an application has hooked INT9, otherwise the standard vDos keyboard handling is used. As a result, all keys (like numeric keyboard) should now also work outside of XYWrite".
Alas, a non-437 code page compliant Courier screen font which I spent considerable time customizing won't work in this version, but that's likely an anomaly of the font itself.