Thanks for reporting back. ^ You were lucky if your flight arrived at gate 50. As you arrived from Asia (according to your previous post) you must have arrived at Z50A (arrival level). It's actually one of the nearest gates to the central security control! The new part of pier A/Z is 780m long so it's a much longer trek, for example, from Z69 as you see on the last page of this map.

Although you don't mention you must have cleared transfer security first, then went two levels down to passport control. There is an alternative route for passengers connecting to a Schengen flight to go straight down to passport control at the end of pier A/Z (instead of following the signs to the right for connecting flights), go landside and clear security into A departures but passengers not familiar with FRA should not need to know this. Unfortunately the extension of Pier A/Z has not improved the situation as it was intended especially for connecting passengers.