We signed up around June 9th. Day may be off by a day or two. We were the first family through our turnstile. I pushed DS with a light jog until we reached a CM stopping us to line up for JTA. We were the 2nd family in line, but I let a family with two kids ahead of us. We got slowed down by having to park the stroller (and the line kept going) but the family I let ahead of us took DS and I ran again to catch up. We were the 3rd to sign up. I picked the time we wanted (11:10). When I was leaving the sign up I ran into the line of people to sign up. It was massive. I had no idea! I actually had people int he line telling me "the end of the line is back there (pointing)" like I was trying to break the line. It was a little more intense than I expected.
I would get to the DHS front gate before they allow all PPO ADRs in (that's usually around 7:45a). Get in line for PPO ADRs (usually to the left). When allowed to enter the park, go straight to JTA registration before checking in for your ADR. You should get the show of your choice.