With a decent encoder (and most are decent these days) VBR at V0 should be transparent too, and is much smaller than a fixed ratio of 320kbs. I'm not entirely s

With a decent encoder (and most are decent these days) VBR at V0 should be transparent too, and is much smaller than a fixed ratio of 320kbs. I'm not entirely sure how it compares to Opus, but it's a better target than 320kbps fixed rate.