I’m always curious- what time do you think would be best for this? For many reasons 6 AM or 7 AM is actually worse for many people, especially people on the West Coast. As a parent, I always hated that early morning time start for WDW dining reservations, and fast passes because it was always when I was juggling kids and getting them ready for school. I don’t think there really is a perfect time. And no matter what time you set it as people are going to still want those early port arrival times and the competition is still going to be tough.
I’ve also very rarely seen open boarding happen more than 90 mins after boarding starts and I kind of wonder if the stress is worth the potential extra 90 minutes on the ship for a large group, but that’s just me

. I like getting more time on the ship too, but at a certain point that cost benefit analysis has to be weighed.