Who knows exactly why I was approved, but I went into detail about each provision that was listed regarding a waiver--like having a VO and PIC trained in night operations, see and avoid procedures (I actually made the point that at night this was easier than during daylight; and that sound also usually carries further at night [typically]). I also provided a URL to some Lume Cubes I had bought, which I had tested myself, and pointed that out in the application that I was able to see the lume cubes flashing 5 miles away--in excess of the 3 miles requirement. I think they mostly likely to see that you've put some thought and "work" into writing up an essay as though you're pleading for your life, and convey an attitude that you're asking a huge favor, and understand just what great responsibility you accept for having this additional privilege.
BTW, those Lume cubes are bright. I noticed that street signs would glow very bright each time the lights flashed, while recording video 200 feet AGL.
I don't use them anymore though; as they tend to overheat in 15 minutes, and shut themselves off... plus they're heavy and reduce flight time by a few minutes on a P3P. I now use 4 Flytron Strobon Cree's on a P4P which are brighter than the first generation Strobon's which I also have--but only use when riding my bike at night. I haven't tested the Crees, but they claim 3 mile visibility at night.