My default is passive; if you train a lot and do a ton of ready-up reps in the daytime with your optic, it translates to doing the same at night. If it's a more dynamic environment, I just press the switch for my laser as I'm presenting and I can trace the laser onto whatever I want to aim at to be just that tiny bit quicker. As I'm bringing my optic up to my eye, I can see both laser and dot through my optic and there's also the added benefit of the laser providing more illumination on the target to see through the optic.
Passive works great if you're ambushing or initiating a firefight but as soon as lights and lasers and IR illumination start flashing everywhere, it loses a lot of effectiveness and it's better to join in on the chaos. If I'm being engaged and I have to transition between targets and it's really dark, I'm using the laser with powerful IR illumination every time.