This is really interesting to me. I do a lot of mapping of natural surface single track trails (for hiking and mountain biking) along the way be sure to properly name things, add intersection markers, and create relations (routes and superroutes) to document the systems. The biggest downside thus far is a good way of displaying the data. mtb.waymarkedtrails.org gets close, but I'd really like something that displays…
The developers are fairly consistently adding new content as well, might not hurt to reach out.