Jim Salter on Nostr: sure, that works. I was assuming that this was hypothetical and an exercise to trim ...

sure, that works. I was assuming that this was hypothetical and an exercise to trim the absolute least amount off the total capacity of the drives in play!

You'll lose a bit to padding with five wide Z2, of course--enough so that you'll be back down to roughly the 50% SE that mirrors offer. But you'll have true dual parity on both vdevs, which mirrors *can't* offer, and I suspect you still prefer.