Do they make any promises about persistence of local NVMe after something like a full-region power outage yet? Because if you can't do durable commit on a single-region cluster that will be just temporarily unavailable without loosing committed data if something like that happened, it's not quite there unless you still stream a WAL to storage that they do promise you will survive a full blackout of all zones that store (part of) the data.

Worth noting the c8gd local NVMe is ephemeral so you'd need to pre-stage the data each run, but for a benchmark like this that's actually ideal since you avoid EBS cold-read artifacts entirely.