Right now I'm trying to finish up the last of my Side Quests, before finishing off the Catacombs and starting on Karamelle.
I'm a completionist, and I get a bit antsy otherwise and I'll have trouble enjoying myself. Unfortunately, some of these final side quest bosses are actually pretty tough to solo, even as a Necromancer.
I also have things like "The Tower of the Helephant" & "The Pagoda of Harmony" to scratch off my list, since I didn't do them when I was the appropriate level for them, but I can run through those solo easily enough. Currently on my way to finish the Waterworks Dungeon as I type this. Guess I have to rescue Lieutenant Culpepper and make my way through Lower Zigzag too.
I'm definitely not progressing to new worlds on my alt characters until I finish off all side quests. Going back and doing them is such a slog.
No, the real challenges I'm facing right now are: Hercules Poirot, The Shedder, Mr. Dead, Sphinx and Yowck.
However, with the new world coming out literally just this morning, I don't anticipate players will be queuing up for these battles very much. It may take hours to find a team for even just one of these boss fights.
Adding the ability to join the waitlist for all of them at once would make situations like this more bearable. I select all the relevant content I'd like to team up for, and then whichever has players join first takes precedence.
After finishing the Dungeon, one can automatically be placed back on the remaining waitlists. The one you completed is automatically removed if you choose Questing. If you choose Farming, you stay on the waitlist so you can run it again.