Wouldn't tendermint with lotionjs do the job? Honestly, I believe Tendermint is a step up from Steem's current consensus system and I'd like to see it switch over.
Also, is it going to ever be possible on Steem Engine for SE tokens to have inflationary rewards that do not require a bot with active key access? This centralized feature is the main reason why I wait for SMTs over coughing up the 3000 ENG.