Privileged sequencing is equivalent to custody because you have a million ways to steal money by creating systemic unfairness in trading. That’s why markets regulation is separate from clearing houses, brokers, custodians, etc. It’s about risk, and you still have all the same risk with a centralized sequencers as you do in traditional markets, which are already verifiable and continuously surveilled. Separating execution from custody isn’t a new thing. It’s existed for decades. Single sequencer layer 2s solve the custody problem. They don’t solve the market integrity problem. You need to solve both by decentralizing the sequencer.