I'm not a smoker but I have a friend whom I travel with who is. Long story short, there are semi-designated smoke stops (technically "fresh air/stretch/smoke stops"). A number of these are crew change stops (SAS will be one, as well as being an equipment shuffle stop; I believe ELP will as well) and others are high-volume pax stops (not really applicable in your case).
The general rule is that the conductors can ax a stop in the interest of time, but the conductors are also not inclined to do so for the sake of everyone involved. Usually if a stop is a smoke stop you'll have time, at a bare minimum, for a quick smoke. Additionally, if a train is early (probably not applicable in your case) at a station it can become an "extra" smoke stop since they can't leave a station until the posted time. I've seen this happen a lot on the Silver Meteor on weekends (CSX treats that train reasonably well, and the light freight traffic on weekends means I've seen every second stop become a de facto smoke stop because we didn't have any other meets).