The project is just a few years old, and it takes a very long time to produce one of our ebooks so the rate is rather slow. But we're getting more and more contributors :)
I'm glad you picked Don Quixote, I personally took the time to transcribe the over 900 endnotes in our production from the Ormsby edition. AFAIK our edition is the only digital transcription of those endnotes available online--not even Project Gutenberg has them yet. Enjoy!
I've been meaning to read Don Quixote in Spanish some day.
Slightly off topic: Would there be scope for a bilingual epub format for wide-screen devices displaying native text and translation side by side? This could be useful for Ancient Greek and Latin verse, Norse sagas, devotional readings of sacred texts, Hamlet in the original Klingon and even automagically machine-translated documents.
Dead-tree parallel texts have something of a market at the foreign language section of one's local book-store.
We track them internally. If you want to work on one, send a note to the mailing list and I'll let you know if you can start or not. Also see our list of wanted ebooks: https://standardebooks.org/contribute/wanted-ebooks
There's no subreddit but we do release announcements on the mailing list, and we have an OPDS feed you can plug in to your reading software of choice: https://standardebooks.org/opds/
I'm glad you picked Don Quixote, I personally took the time to transcribe the over 900 endnotes in our production from the Ormsby edition. AFAIK our edition is the only digital transcription of those endnotes available online--not even Project Gutenberg has them yet. Enjoy!