For your appliances, maybe look at the commercial market. You usually get minimalism and quality material (lots of stainless steel). Often good reparability, but not much open sourcing I am afraid. And certainly several times the price.

Note that commercial dishwashers are not at all like their consumer counterparts. They don't really wash the dishes, they sanitize them after they have been properly rinsed, and a cycle takes minutes instead of hours.