Inventory Open/Close Periods

We have a requirement to have different BOM Configurations for the Same Item by "Supplier."  Since we have a limited number of Suppliers we were planning on creating an Inventory Org for each Supplier, and therefore each Inv Org could have it's own BOM (if someone knows of a better way to accomplish this - feedback would be greatly appreciated).  So my question is:

If we have Inventory Orgs that we are setting up only for Item attributes, and will NEVER have transactions flow through them, do we have to open/close Inventory Periods? 

Thanks,

Bob