The US Naval Institute Proceeding November 2021 issue has an article that argues
While command center staffing only marginally increased, the creation of sectors diluted SAR expertise by increasing watchstander knowledge and training requirements to include those necessary for all Coast Guard missions. In particular, the operations specialist (OS) rating has endured the lion’s share of changes to core watchstander roles and responsibilities. As a result, the entire enlisted rating—which performs critical functions in the SAR chain of command—is at risk of collapse.
I was a district watch stander back in the stone age, before we had software to help planning, and before the Sector reorganization. I stood a 24 hour watch with an enlisted assistant and even then we did more than SAR. While I have not seen any indication his conclusions are valid, I am too far removed to trust my own opinion. I would welcome comments.
Chuck Hill's CG Blog 
I remember standing comm watches at the MLB station. Granted, this wasn’t a sector watch but our duty was 24 hours which included sleeping in the comm room at night with the radio turned up full blast. On the weekends this became a 72 hour watch and during the busy summer season it was not uncommon to be up the entire weekend.
It sounds like the Groups handle this now?
imo the sectors and sar coordinators are just adding a layer of beuacracy in to the sar decision making process that used to be handled by stations , coxswains and patrol boat cos/oincs. had a masterchief on an 82,, many years ago, salty as f. if he didn’t like what group told him he did it his way and not always politely. always worked out well