For the benefit of others avoiding stress: I see absolutely no reason to try to be in a virtual queue before 7am. I made four different Cantina reservations this past week (not all for me!), and 3/4 times I simply jumped on the page around 7 and refreshed until the day opened up (was 7:01 most times). I’d get the “sit tight, friend” screen briefly and then go straight to the booking page. I was online all of the other days around 7:15 and there was still tons of availability (that’s when I booked the fourth day). Some days, there were reservations open until 10 or 11am.
You do want to book around 7, especially if you want a specific time, but there’s no reason to be in there early like I keep seeing people mention.