Most everything stopped at Cumbres. I can't think of anything that would have gone through without getting water or doing a required brake inspection. However, those activities had nothing to do with the train order signal. The signal was all about getting new train orders. As long as the agency was open, all trains stopped, and the conductor signed the train register located in the depot.
While I'm not positive, after the depot closed and was torn down, there was no more register book at Cumbres - at least I never heard of one there.