How does UTX night lighting work?

I use REX to change my lighting, like runway lights, aircraft nav lights, etc. Questions are:

1) Does REX have any affects on UTX's night lighting system when changing up the light textures. Does UTX call for halo.bmp?

2) Does UTX night light use it's own lighting system and custom .bmp file?

I am in the process of fine tuning my runway lights at the airport, ie: papi, approach, apron, centerline, etc. and don't want it to interfere with anything else like the street lighting and such. As long as REX and UTX night lighting doesn't conflict with one another.