Before I begin, I just want to point out that there isn’t just one way to do things. Even photographers will use different light setups based on their artistic style. So, do what feels right for you. Now to the answer.
The light node setup adds shadows and a soft glow to give the look of a large umbrella reflector and light. This is common in photographing people and products. Cars and larger products usually use straight lights or light with a defuser gel, and reflector boards.
My point boils down to the fact that because your trailer is so large the node’s effect is very minimal. If you like the effect leave it. I personally don’t think the slight effects is worth the added render time. Plus I try to match real world common practice.
