Very good information - and nicely presented to summarize it. This post is a keeper for future discussions for sure.
We always new proof-of-stake related systems would be letter in the long run than proof-of-work (unfortunate situation, but very true)
Yeah, harder to pull off, but still able on PoS, but cost you a lot more and not very enticing lol. It hasn't been done yet, while it has been done to PoW ;)