I intend to run Gardens of Ynn at some point because it will blend it pretty well with the whole fey vibe we've got going on here.
In which case, maybe check out "The Stygian Library" as well? Both of them are easy to drop into anything, but maybe a little too procedural. More interludes than destinations?
If you're happy with your campaign world then Planescape is right out, since that's an entirely different millieu, but you
can run "The Final Boundary" without committing to a million boxes and paraphernalia if you want to give it the old one-shot try some day. I think you'll like it since the setting is more about the colourful NPC's (that are really easy for the DM to step into the PC's to interact with) and far-out imagery than trap-finding and tactical set-pieces.
If B3 is too gonzo, then so is DCO (plus it's desperately bleak). One hell of a good read though.
It got slapped down by this site's erstwhile host (much to my disappointment), possibly due to it being a 3e product, but "Vault of Larin Karr" had lots of slice o' life wilderness adventure to drop into a campaign as well.
And yeah, Castle Xyntillan is an absolute gem!