Work required for ROA1 level of “workshop characters” is exponentially higher in the new art style and engine. When/if this game gets Steam Workshop, it’ll probably end up with more “tweaked/cloned” characters than totally new wacky MUGEN stuff like ROA1.
Balatro Mobile Maker works because the game’s engine (LOVE 2D) is designed from the ground up to be multiplatform. It’s trivial to “port” compared to other engines.