If more complicated protocols become a major part of bitcoin's transactions, what the resulting MEVil looks like in practice is something we should all be clear about.

@7d5x9 (from Twitter) and I sat down and wrote about the best (bad) solution we'd have if MEVil becomes big.

In that world, complicated transaction construction algorithms would put immense pressure on mining centralization which, left to develop on their own, would drive horrible outcomes for Bitcoin.

Instead, we propose the best idea we have - containing the damage to as small an area as possible by allowing the MEV(il) extractors to only bid for a small part of blockspace, leaving miners to pull from the public mempool for the rest. (It also enables more competition between MEV(il) extractors than ethereum's PBS by splitting the block space market into many smaller markets on a per-contract basis).

It still represents a dramatic increase in centralization in the mining world, with marketplace centralization potentially allowing for exclusion of certain miners, but its way better than letting MEVil play out naturally.