In general

As mentioned over on the main page, two characters will occasionally perform their respective Dual Heat attack from Eyes of Heaven.

Diamond Is Unbreakable

In chapter 3, when Josuke comments that ghosts are as likely as him being a gay sailor in another dimension, his girlfriend Pinkie Pie replies that his Alternate Self is a hetero sailor with four balls, which he finds more believable.
In chapter 28, Pinkie Pie immediately figures out that Rohan is being possessed by the parasitic Stand Cheap Trick and the events leading up to it, not too dissimilar to how she figures out that Twilight Sparkle was a magical pony princess from another dimension and why she's in their dimension in My Little Pony: Equestria Girls.