Salty, I have never conducted a trap out. But what little knowledge I know is: I thought the nuc entrance was supposed to be close, right next to the cone entrance, side by side. In other words, the nuc, trap box, entrance is close as possible to the original entrance. The point being the bees will enter the nuc as is now the only available entrance due to the cone blocking the original entrance.
Like I said, I have never done before so consider.