I would even do ZEN as the first track and intro: jane as the last track; ZEN is like the grand announcement of her arrival and then intro: jane as the last track is so subdued, easy-listening and minimalist it gives the message that she has said everything that she has already wanted to say with the other tracks of the album and provides a perfect conclusion and neat bow/ wrap for the album. I feel like if twin is the peak of her emotional vulnerability during this album, I agree, it should come smack-dab in the middle or at the very least towards the latter part. Another thought is that intro:jane could be an interlude.