I HIGHLY suggest you go the pan route. .dup doubles the number of UGens being used and is less efficieint even if it is less to type.
SuperCollider makes no assumptions about WHERE in a speaker array a sound should be. I use a 16 channel set up, so people use 2, some 4 … and when you get to more sophisticated signal processing and routing, you’ll hit many less limitations with your mono source being placed where you want it to be. Defaulting to stereo would cause a larger number of problems in the end.