The SMT code is still available, and it was a non-Steemit dev, @howo who was doing final testing on it paid for by SPS. There might be, and probably is, some further refinement needed before it could be considered deployment ready but I think it could be done in time (and quite frankly I wasn't convinced it was going to happen very quickly with Steemit working on it either).
The others I don't know.
Okay, I was not aware of that. That would be very good news for Classic Steem if we go down that path.