I think the OP is referring to flying into CGK, not out of.
All international flights are in the process of moving from T2 to T3. MH recently started, I just got an email that TG will be moving soon.
I fly business into CGK often (however, NEVER GA) and have never offered or seen fast track thru immigration. GA may be different.
Originally Posted by
Daxiuyi
For GA that's Terminal 3. At Terminal 2 (if flying SQ, and several other airlines IIRC) you can use Fast Track immigration if flying Business. Instead of walking to the right past all the check-in counters to immigration (and then doubling back airside past all the shops to the lounges), you can clear immigration to the left of the SQ counter, go through a magic door and end up airside in front of the SQ (and other) lounges.