Inventory Commitment Preference IN EDI Orders

We are currently using 9.0 and have setup P4210 preference option for Inventory Commitment Preference to 1, when orders are manually entered it works fine, however when we try to create orders through EDI850s it ignores this processing option when creating the order. Is there something I am missing in the setup to make this work when the orders are sent EDI, or is this an issue with 9.0? And also in my case I would like to override MCU set in F47011 and F47012 to one that I've set in Inventory Commitment Preference 06 . We need to split some