Yep, I have a more optimised model of stacking than my wife’s ideas. This has lead to “discussions” (still at a friendly level) and the dish washer being placed in my list of responsibilities.

I think optimal configuration is very much a NP complete problem.

Just because a problem is NP-complete doesn't mean it's infeasible to produce "good enough" approximate solutions. The traveling salesman problem is a great example of this.