Airside transfer between terminals FRA
I want to use the Diners club lounge at Frankfurt which is airside in terminal 2 before flying Lufthanse out of terminal 1 to Beijing in November.
I have previously transferred between terminals on land side using skyline but that takes half an hour or more because of the need to pass back through passport control out of T2 before going back through security and passport control again at T1.
Is it possible to transfer between t2 and T1 while staying airside (non Schengen)?