i found this website of all (Deck AND engineering questions) as a free Q&A source. They require you to register and sign in, but it is free (they do ask for donations) and seems to work flawlessly.
Any other users with any experience chime in.
I was looking for a way to get the 100 or so questions for an AUX sail endorsement, and hit upon this. They are set up to do either all of them, or random sets of 20 to practice on.