Sequencer-Enforced Invariants: Catch-all Discussion

[sam-iamm]

This is meant to be an open discussion board for Sequencer-Enforced Invariants on the OP Stack.

Design Doc: ethereum-optimism/design-docs#30
Proposed Solution Reference Implementation: ethereum-optimism/optimism#10791

Design Doc TLDR:

• Our motivating use case for "sequencer-enforced invariants" is safe sequencing, where exploit detection algorithms are used within the sequencer to censor smart contract exploits. Additional use cases may include MEV capture designs.
• Forced L1 -> L2 transactions can violate inclusion and ordering invariants added by a sequencer.
• We propose a SystemConfig toggle that allows OP Stack chains to control the ability for a sequencer to enforce inclusion and ordering invariants related to forced L1 -> L2 transactions.

Please see the design doc for additional motivation, details, and alternatives!