Those and other nooks and crannies. For example I did not know about the note that tells you which thing to pick for the coeurl boss because no one had bothered with it in groups. I also did not know about the loot chest in the room with the clams since everyone skips it.

I have taken to either going back and soloing old dungeons to explore it all and read the notes or doing them with duty support so I can take my time exploring.

Honestly if someone in the group is a first time in there (and its easy to tell who really IS a first timer) I am more than willing to slow down and let them see the sights. Then again I have been playing for 4.5 years and am only halfway through Shadowbringers. I take my time and enjoy the journey.