[interestednovice]

I think what happens on the NC is that Gallery A in NBH takes the feed for the UK, and this happens like a soft-opt where a switch occurs at 5:53am or so, but it stays with the global feed until the end of the 5:30am bulletin. That gallery then plays out trailers and the NC countdown before cutting up Salford output at 6am. The programme then “runs through” Gallery A until the end, when once again they cut away and play trailers just after the “You’re watching BBC Breakfast, the time is 8:59”. The countdown is played again, they cut up the NC global feed and soft opt again before leaving the circuit.

BBC One playout handle it separately for BBC One, of course.

I just said “Salford opt” as a shorthand really, I hope it didn’t cause any confusion.

Anyway, it seems Technologist has worked out the real technical reason - as ever, a very knowledgeable and interesting technical post!