I think that the TurnKey RPi port has stalled (again) :( . The person I mentioned did get BitKey ported to RPi and he sent me a copy. However he hasn't published how he created it so we can't replicate it. Besides, I don't think that his methods would directly transpose to the other appliances as BitKey is a different use case.

FWIW we have the "issue" noted on GitHub. And we have put up a $200 bounty on it on BountySource.