Not sure if he’d appear in the crossover, but there’s nothing stopping him from popping up at some point in Brothers Lost. Tiny Dean and Bowman would make quite a pair, and I can’t imagine the snark would ever end. Dean can’t pocket Bowman to solve his problems anymore. Now, he’s pocketable as well, so they better behave themselves or Sam will be encouraging Jacob to pocket them while he stays the lookout.

Dean meeting a small version of himself will always have his hands full XD But I can’t help but think how cute they’d be working on the Impala together. Big Dean has a little version of himself that knows all the car stuff he knows and is able to fit into all the tiny corners of the car, and little Dean has a big version of himself to boss around if he needs to move something heavy and they’d probably be on the same wavelength the entire time because c’mon. It’s their baby. She must be treated right.

BL Dean will be a little jealous that BA Dean can just go to the store and buy himself some pie though. Hell, he’d probably get a slice from those humans around if he even mentioned that. Guilt the tols into giving pie.

There’s a thousand possibilities for how it could happen! XD Just imagine BA Sam running into a tiny Dean in the walls and doing a double take. How did his brother get so small?!?! 

The BA’s won’t have the sensing thing as completely as the BL’s. Their little knacks come from the curse Celeste put over them (a little bonus for losing their size, something to increase their survival chances). BA Dean might be a little jealous that his tiny counterpart can track down pretty much anything if he figures out that he needs it.

The BA bros teamwork won’t be as seamless as the BL bros because they spent half of their lives separated while the BL bros have never been apart. The BL bros are also a lot more dependent on each other because of this, and stress more if they need to separate for long periods of time. Jacob will notice this if he only has one brother around.

XD BL Sam certainly has keeping Dean in line a lot easier than BA Sam. He can haul Dean around all he wants while BA Sam has to figure out how to keep his giant of a brother calm (or rile him up more).

They have their Deans cheat codes.