Kil - I think if more people concentrated on YFT jigging, even during the day where fish are confirmed, the G.O.M. would be a consistent producer of jigged YFT's.
Did you see the Nyati report of the daytime topwater bite? They caught two YFT's (~60# & 90#) about 20 minutes apart before they continued marlin fishing!
Most bluefin are caught on jigs daytime.
We catch yellowfin tuna and longfin tuna on jigs at night when water temp is high and we start to catch them on jigs when water temp drops under 65 degree at canyon. But we found tuna sometimes eager to hit on jigs daytime even water temp is high when we tried jigging after we got tuna on troll as long range boats out of San Diego boats do. You never know until you try.