Controlling Supplier Access Using AML / Manufacturers tab

Hello,

We are investigating the use of Manufacturers tab (AML) to control which assemblies and components each of suppliers can see.  For example, if an Item has "Mfr A" and "Mfr B" on the Manufacturers tab, we would like to configure roles & privileges so that any supplier user from Mfr A or Mfr B can access that particluar item; however a user form Mfr C would not be able to access (or even see) the item.

The problem that we are facing is that in order to do this, it would require us to set AML at all levels of an assembly (from assembly down to the sub-assemblies & sub-components).  Is there a way to achieve this without developing a Process Extension to proprogate/push the AML details from the assembly all the way down (parent-to-child)?