The problem I see here, though, is what if a miner is also voted as a DPoS witness without his knowledge by someone with a lot of vests?
That would also mean that he would not have updated his witness with the command:
update_witness
so he would not be on the dpos witness list...
bad even if he is in the list (because in past he was an active dpos witness) but now he is not active anymore, this would prevent him to get included in a queue to produce witness blocks I assume...
https://github.com/steemit/steem/issues/278
Fair point, and that git commit will definitely help prevent this. I was told double signing penalization was deactivated, so it's a non-issue for now anyway.
Having said that, there's a user who is currently undergoing the scenario I laid out! @proctologic set himself up as a witness, obtained a substantial amount of votes, and decided he'd rather mine instead. He unvoted himself as a witness, and began to mint PoW. But he's still high up on the witness rankings due to others' votes. An interesting predicament.