For me, I actually don't want to be NC'able too long into my SC stint, as frankly i'd rather be back on a nebulous promptly-available status. I figure as an in-base guy, you drop NC when you're assigned SC the previous day, then from that time until the next day right at your SC start, it in theory prevents CS from dropping a trip on you in the first two hours. Then the next day once SC starts, check your sked in ICrew and you're back on promptly avail and are no longer on the hook to be there right at two hours after the start of your SC.