You've seen her more recently than I have, and talked to BAE people who deign to enter the hangar. From their lofty perches in their air-conditioned offices, my sources may be a bit 'chief Koala' like.
Like you, I found it interesting that BT001 is so much more advanced than the second UK IPA (which wasn't even in the shed last time I was there), n'est ce que pas?