Thats awesome about the GUCs, but nearly opposite of my experience. Five years ago, I could routinely clear at time of booking. Starting about two years ago, I wouldn’t clear until weeks or sometimes hours before a flight. Now I’m lucky to find an itinerary that only has time-of-booking UGs on domestic segs, which you obviously don’t want to book without blowing your whole cert. My routes are 100% TPACs.