Just finished my Cairo Turnaround without any problems.Contacted Cairo station manager of turkish airlines prior and was granted Meet& Asist Service while aircarft door opens.
I recieved boardingcard ex Cai at IST Transferdesc before leaving for Cai.
Station manager of TK in Cai also handed me a back up boardingpass out in Cai.
He also informed transfer desc to stemp my bordingpass immediatly and promised me to wait till I reach the aircraft.
That was not necessary as I was back at the gate before boarding back to IST started.
Hole transfer took 15-20 minutes.
If you need more informations feel free to PM me.