Here is our tale!
We left Dolphin at 6:30 this morning and walked over. It was actually a beautiful walk and not nearly as long as I was imagining. Once the underpass to the road was visible, I could see the HS parking lot and realized it really was just a hop skip and a jumppppppp. Anyway, we got there before 7 and yes, there were lots of folks but once we got into the park, we were probably in the first 120 by the Galaxy's gate.
Here was our strategy: I have iphone 8 and hubby has iphone 7. My app was updated and his was not. It has been taking waaay too long for my app to get those fireworks going. We had an app race and when I saw how much faster his was, I asked if we could switch phones at the crucial appointed moment.
Okay, OKAY, I TOLD him we were switching phones.

I was the one who has been doing practice sessions and he's not super techie, or as obsessed as I am.
I made sure both our phones were fully charged and we were OFF of the wifi. I had deleted my app the day before and reloaded it. Hubby would be trying for a group at the same time as I would be, with me using his super duper speedy unupdated app.
At 7:58ish, we both opened the app, then went back to our home page and watched the clock hand ticking....ticking...ticking...
With about five seconds to go, I started counting down and at 7:59:59, I went back to the app, clicked the find out more, then My Status, the clicked Join a Boarding Group. We got boarding group 18. I yelled out even before my spouse, on MY phone had a chance to join a group.
So honestly, I think it comes down to the fastest person, with the fastest app and a keen eye on the time. And good luck.
The ride stopped loading new groups at group 12 and we waited for a good bit. Finally got called in at 11am. Make sure everyone has gone to the bathroom before entering the line because once you're in line...it can still be quite a long wait. One hour for us and we were moving most the time. We were thinking of how this might be tough for sensitive kids. All in all it was super fun and amazing and I feel satisfied all of the pre-planning paid off.