Enabling AME for only one operating Unit?

Hi,

In 12.2.6  Has anyone tried enabling AME for Purchase Order approval only for one operating unit.

In comparison to 11i where you just enabled AME in the document type definition, R12 version says one has to do there as well as the document styles.

While one can do that, the problem is that even if lets say I create a new document style, there is no way, I see I can attach it to the document style standard Purchase Order.

We necessarily want to use the PO creation in the standard PO form.

I tried understanding below note. However that does not tell me if after say application of the patch , there is no more the need to set up any changes at the document style level.