Comment by roryirvine

Do they at least allow you to set your own schedule for upgrade windows? That way you could schedule them for quiet times of day, minimising the likelihood of there being significant replica lag.

It's common to do this on AWS and the other hyperscale providers (though, of course, they tend to do synchronous replication anyway, meaning that this particular failure mode wouldn't apply) - upgrades are a common source of unforeseen issues, so it makes sense to minimise the potential blast radius by running them out of hours.