Is there a transit area in Terminal 1 or will transit passengers have to clear Philippine immigration/customs before continuing on to other flights?

I've entered the Philippines via Terminal 2 once and know that multiple security checks just to get into the terminal and gate area can be lengthy.

If there is a transit procedure at Terminal 1 that keeps passengers airside, it would help immensely; otherwise, going through all the motions (getting back up to the departures level, getting checked twice before reaching outbound immigration, and checked another two times before reaching the gate seating area will be a real PITA.

Thanks!