I went to the party last night and am willing to answer any questions.
Some things noted:
-Character trails were spectacular as always! Ernesto was definitely the longest line, but the CMs know people are wanting to stop and watch him and they try to push you along. We got in line all the way near the entrance to Webslingers, but it was only about a 10 min wait. Madame Mim was also wonderful, and Sid was so great (must be a dream job to basically just be a jerk all night).
-Characters do have to switch out. I know someone waited for Ernesto but when they got there he was gone. Make sure to check if the character is out before getting in line (although they could always leave mid-line). Cruella seemed to be the slowest moving trail for me, but they may reorganize that one a bit.
-Character meet & greets were long. And the characters take a lot of time with each person, which is good for the guest meeting, but super annoying when you are waiting.
-Parade, you prob should be able to get a front row spot 20 min beforehand. Even walking up right before parade, you should be able to get a good view right before.
-Villains Grove was the same as previous years, but it's still spectacular. Our longest wait, but we prob didn't time it well (about 30 min wait at its longest).
-For Kingdom Hearts, it was a long line (my friend wanted to meet them). And don't forget Mickey needs to leave to be in the parade. They have Donald, Mickey, Goofy. Sometimes meet in groups of 2, sometimes by themselves.
Anyways, let me know if you have any other questions! It was fun and I'm actually going back in October so I can enjoy it again.