I've worn my commando sweater in. When I first got my kilt it was winter and it was a little big for me. I looked fine. Having met McMurdo, I've found a reason to pound back the beer so I no longer need the bulk. Out causes the sweater to bunch up around the sporran or gets caught up on the buckles just making it look sloppy. A commando sweater is a form fitting sweater so tucking it it just streamlines the look. But yeah an Arun sweater leave out.