I had the same experience and would give the same advice as
@Jackson as far as camping close to Mr. Bubbles so you can go early in the morning or at sunset to avoid other people. Definitely a popular place now. Thanks Youtube.. lol! While your in that area you may want to take the cutoff trail over to boundary creek trail and sit in the rock hot tub below dunanda falls- it has a better view with the falls right next to you anyway. Its also very popular right now- so I'd recommend a mid week trip to Dunanda falls, again with a camp close by.
9D1 has a cool thermal feature right next to the camp and the river. If you stay at 9B4 I'd recommend a hike up to Ranger lake or over to Ouzel Falls if you have time. both really cool off trail places. On advice from
@scatman, several years ago we hiked up to Ranger lake on a short mile day and saw 4 moose and a black bear. Ranger lake is kind of creepy at dusk. Don't go off trail if your alone though!
By the way, how early did you draw out? I got the 11th.