I think it would be really cool if we had industry specific ploppable shops that sell what the unique factories make. For example, a ploppable pastry shop that uses only what the Bakery makes. But then also increasing in size (not growable), i.e: a pastry shop that sells baked goods, a corner shop that sells food (from the food factory), baked goods (from the bakery) and lemonade (from the lemonade factory), a clothing shops that sells clothes and sneakers (from the unique factories), all the way up to malls that sell everything that makes sense for a mall. Even if just the shopping centres and malls in the unique buildings can be modded to accept goods that make sense and turn a profit would be really cool!