Ok, at JFK (could not use the kiosks as all busy) went to get a paper boarding pass. Checkin lady said there was no way they could add KTN (is coming soon she said). Prints the boarding pass and lo and behold it says TSA pre, so I guess adding it to the AA booking helped. Pointing that out she says ‘yeah, but it doesn’t work yet’. Waived it at the security guard and indeed got the TSA pre light treatment. Shoes can stay on, rest comes out.
So, it sort of works, now we just need a TSA pre lane at T7.