Currently $planCacheStats logic serializes only PlanCacheEntries as result of this stage and QuerySettings are not present there, because they are part of the key.

Having QuerySettings as part of $planCacheStats would help during diagnostics, therefore it would be valuable to have it there.

In order to achieve that we could modify the serializer of the PlanCacheEntries and let it take PlanCacheKey as well. Then we would include PlanCacheKey.QuerySettings into the serialized output.