Not easy at MAJ, doable at the FSM islands if you are among the first off the plane, all but impossible at KWA.

Why is MAJ not easy? The same immigration officers process inbound and outbound passport control for the flight. They first process all the outbound passengers, then passengers are put in a departure lounge (post security and post immigration) waiting for boarding. Security closes and goes home because there are no more passengers. Then the flight arrives, and the immigration officers go to the arrivals window to process inbound passengers.

If you go through inbound passport control, you will have a hard time getting back out onto the same flight because security and outbound immigration are both closed. You will have to plead for an exception, all in the short time that the flight is on the ground. Good luck.

Could you just go to the inbound immigration window for your stamp and do a 180º the same way you came, like in some FSM stations? No, because the arrivals area at MAJ is non-sterile, and you can't get into the sterile departure lounge.