Honestly, if Logan is hunting the sprites, I don’t feel like Dean would have any remorse about using the mushroom to make him small. Make him the prey.
So Good News, he isn’t shrunk by the Trickster’s tricks.
Bad News, he wasn’t shrunk by the Trickster’s tricks.
Dean in Brothers Found is certainly likely to hang onto that mushroom and turn it into a little lesson on perspective for certain people… He’s not the type to feel any sympathy for people like that.