@cbnorman, yes. sadly, it looks like we don’t/can’t support Debian reliably on MAAS. see the discussion in this post, whose title really should be “How to deploy Debian in MAAS?” (i added the question-mark). there’s back-end development we’d have to do, which we don’t have bandwidth for atm. sorry i don’t have better news.
would an Ubuntu OS do what you want?