Good point. Though the "internet wisdom" nowadays is to not add vdevs to a pool that has already seen use (in this scenario there will be a lot of use) since th

Good point. Though the "internet wisdom" nowadays is to not add vdevs to a pool that has already seen use (in this scenario there will be a lot of use) since the pool will be very unbalanced and there is no way to rebalance it. Also negating many of the benefits of mirrors over raidz. But that advice might not be relevant for the use-cases discussed here, something to keep in mind. I meant that home-users don't have to be limited by 8-drive setups.