I have three Jogglers now thanks to a kind donation, and I'm poking at them a bit more. Booting debian-installer works on all of them as described in
my previous post, which is nice. My plan is still to get an unmodified Debian to work correctly on it to the maximum possible degree, but after that I might see about getting it to play nice with Android 4.2. Not much of an update yet, but we'll see.