I have a question about the terminal state. In your blog post it is phrased as a takeover which is inherent in the proof-of-work protocol in the currency.
It seems to me, though, that as soon as a cabal of defectors successfully captures the mining process, a next generation of defecting cabals would immediately form, using the advance information from the previous winning group, and the process would simply repeat in waves.
That is, what we currently have is a group of miners who all share their information with each other as soon as they find it. That's exactly what a sub-group exploiting the instability you identified would look like once it won.
It seems to me, though, that as soon as a cabal of defectors successfully captures the mining process, a next generation of defecting cabals would immediately form, using the advance information from the previous winning group, and the process would simply repeat in waves.
That is, what we currently have is a group of miners who all share their information with each other as soon as they find it. That's exactly what a sub-group exploiting the instability you identified would look like once it won.