Taipei - Walking Between Terminals 1 and 2 Airside
Hi all. In Taipei International Airport, are we allowed to walk/travel between Terminals 1 and 2 freely, without going through security etc? I am flying out of Terminal 1 in the early evening and want to use a lounge in Terminal 1. My friend is flying out of Terminal 2 later in the evening but can use the Taipei Station to check in his bags early. Can my friend check in his bags early at Taipei Station and then enter Terminal 1 with me to use the lounges and then later move back to Terminal 2 to catch his later flight?
Thank you for all your help!!!