Is it a good idea to bring the steem-engine back to life? Hmm, hard to say, I just remembered the saying that you shouldn't get on a dead horse :-)

True. Every blockchain and its brother already has a layer-2 solution. I'm not sure that recreating steem-engine here adds anything strategic to our ecosystem, and it might dilute the value of STEEM tokens (caused by people selling STEEM to buy the L2 tokens). As you remarked, it seems to me that LEO is the only steem-engine token that really seems to have partially succeeded. That's a whole lot of dead weight for a single success story. There's also a question about whether it makes sense to implement a side chain that would compete with native SMTs if/when we start seeing blockchain enhancements again.

Personally, I think community development efforts should focus on enhancing Steem's unique/core capabilities, i.e. social media. I don't see much point in reproducing standard crypto capabilities that already exist in numerous places (unless it simultaneously enhances the social experience).

I have the same reservations about efforts to create NFTs here. Steem will just be an "also ran" in these areas for the foreseeable future.