Actually I find that I rather want them to be part of a group of military ships. I usually bring them along with Enclaves, SBSs, and most recently, Railpods and NCCs. The group itself moves only when I am getting them into postion, and the MSDs constantly produce Railpods while keeping the rest of the force in full shape.
Though most recently I've noticed that they are decloaking while making ships, though I recall they were specifically buffed so that they could produce ships while cloaked. Did I miss a change? I can't find it in the wiki, and I went back as far as 6.00.