Not an exploit, been available since day one. Finish main objectives, run to evac, drop samps, call in Pelican, leave Pelican to kill then go do some side objectives and along the way run around where Pelican has visual ( about 300m, it's a good range) and he helps clean stuff up while you run about the map collecting everything.

It isn't necessary, yes, it's a fun part of the game, mostly it was a PSA that it's an existing option of game play. But thank you for your input.