Getting pulled over by a trooper is rare, even if you are speeding (unless it's flagrant). It does happen but they tend to focus on cars and I think this is because the ticketing and inspection is easier for them. I've had to get out of the truck and help them find the trailer registration documents in the nose box for example, and I could tell they were a little embarrassed by this.

Weigh stations are simple, you just idle slowly over the scale plate(s) and there is an illuminated sign board ahead telling you to go, stop, or pull around for inspection. New Mexico is the only state I encountered where you actually rolled up to a trooper in a window up at your eye level and had to interact with them, but this was just to hold up a copy of your permit and they waved you through. You didn't have to speak.