Currently Planning optimization doesn't support a custom inventory dimensions and gives error while running the batch. We would like to suggest to make Planning optimization to consider the customs inventory dimension during the planning batch.

The reason is: We (like many other organizations, may be) are using an ISV solution for Product Engineering which allows us to use a custom inventory dimension 'Version' in inventory transactions. As this is part of ISV solution, we expect this custom dimension to be considered by Planning optimization batch. This will allow us to get benefitted using the newly introduced features of Planning optimization.