Thanks for taking the time to post these details.
The only thing that struck me as ‘pump-DOT’ was this claim:
I believe possible ‘centralization of proving’ is an unreasonable characterization of the risks in Zero-Knowledge model for scalable/elastic computation.
Specifically, if you look at Mina you see clearly the presence of a decentralized proof generation and even 3rd party proof market place. More generally, there are several projects exploring proof market places, e.g. Succinct
Finally, it is not clear to me that the computation offered in the ZK model can be a substitute for the computation offered in Substrate based chains.
To that extent making cost comparisons seems unreasonable - unless there is some reason to believe the ZK compute is some subset of that available from Polkadot?
It is true that Mina has some ‘type’ of centralized storage. IIUC, Polkadot has that issue to some degree too.
Also, I believe the Mina protocol does not provide for, nor have on its road map, reciprocal accounts between two Mina chains. In that sense it too is a centralized-decentralized ecosystem, and has the “elasticicity” limit that entails.
As do Substrate based chains. See here for some discussion on that topic.