Doing it on a regular basis doesn't make economic sense, but any time there is a charter on the line during the season, it will meet or be overtaken at least once by a passenger train and probably twice.
I was on a Farrail charter two years ago and we were passed by the WB passenger at Los Pinos siding one day and by the EB passenger at Cumbres another day. A third day we met the WB passenger at Big Horn. The infamous Chama Steam Caboose tipping trip involved a meet at Toltec siding with a passenger.
At one point, John Craft came up with a plan to operate a "Plandampf" type event on the C&TS, which would have involved multiple freight and passenger trains, but that was back when there were five or six K-36 & K-37 engines available. Whether the plan would work today, I don't know.
Michael Allen