finding the actual optimum will naturally be intractable, so the question is what it looks like to imperfectly optimize this objective

Actually even getting the actual optimum doesn’t seem to really address the problem.

You are then OK if the unintended solutions are rare. But it’s easy to imagine cases where they are dense (e.g. where good plans are highly constrained, but plans with a subtle bug in one step have lots of degrees of freedom in the other steps).

So at a minimum it seems like this will only address some cases, or would require some additional analysis.

This seems correct. While an approach like this could isolate one particular distribution over solutions to the problem as the optimal one, you also have to engineer the problem such that this distribution over solutions is desirable.

Actually even getting the actual optimum doesn’t seem to really address the problem.

You are then OK if the unintended solutions are rare. But it’s easy to imagine cases where they are dense (e.g. where good plans are highly constrained, but plans with a subtle bug in one step have lots of degrees of freedom in the other steps).

So at a minimum it seems like this will only address some cases, or would require some additional analysis.

This seems correct. While an approach like this could isolate one particular distribution over solutions to the problem as the optimal one, you also have to engineer the problem such that this distribution over solutions is desirable.