In all my previous airlines we used to preset the QNH when receiving Atis in cruise or early descent, meaning going from STD to QNH, setting the airport QNH and the going back to STD till transition altitude.
That way, when going through transition altitude, you had only to switch from STD to QNH and adjust for the 1 or 2 mb possible change for the last 20 mins.
With this procedure I’m pretty sure that a 10 mb change to what had been preset would have at least raised an eyebrow….