I think that J.R.Ellis would have been a programmer that could have come up with some of the drivers that are lacking for xxxDOS. But, you are right, I doubt if we will ever see anything from him, again. My prediction, open source development will implode, and fall in on itself, leaving behind the human leeches searching for a new host.
Udo has been at this for quite awhile, at some point he may give up, and then that will be the end of one aspect of xxxDOS. I have seen plenty of xxxDOS related web sites that have not had any activity for quite awhile. I do not want to sound like the xxxDOS ship has sunk, but there are fewer, and fewer people walking the decks.