If you want in and out of Pagos, quickly, then chain NM mobs instead of following a train. You will get much more light and exp then if you simply waited for a particular NM to spawn. If you need to focus on light more than crystals, then focus on other mobs. Up until this point, no one cared which mobs you were fighting, once an NM spawned.

Trains do not increase the rate of NMs, since half the train AFKs and people then aren't focusing on spawning NMs around the map. For the most part, people wait for others to show up before pulling, unlike Anemos. There were exceptions, but those were in the minority. If there was a map wide train, that could revert back.