The reason I remember my time at Caledonia is we had to drive to Daytona Beach for another tournament the next day. We teed off at 9:12, finished, turned in our cards, ate lunch and was on the road at 2:20, so just under five hours. The difference between 5 hours and 5:15 is one group, again someone was asleep at the wheel and not managing the groups.
I still think tee times are faster than a shotgun, but it is all about the marshals. Whether you use tee times or a shotgun if no-one is managing the course, 5 – 5.5 rounds or worse will happen. The challenge is how do you pull a group off the course in the WA? I have seen it happen at tournaments I play in elsewhere but I cannot see the WA doing it. I still think tee times are faster than a shotgun