I'm starting to worry that based preconfirmations lead to too much centralization pressure, creating a small oligopoly of shared sequencers and provers. Is this really better than centralized sequencers (which can also give preconfirmations)? At least the centralization here is per rollup and not global.

An alternative proposal: Accept the centralized sequencer, but make forced inclusions super attractive (same price as normal rollup transactions, just no preconfirmations).

20. hacking @ https://www.spire.dev/ 
previously intern Nethermind, epns.io