As you can see --they think little logical and queries us with this type of questions & some times we have to educate them but how far will it works--depends on their mood.
I don't really see things that way, That fact is that SAP has a lot of problems dealing with import procedures and valuations, to the point where we have had to develop a whole module on top of MM just to handle it.
Even in the case of direct PO from vendor, if you have incoterm CIF, the stock becomes the buyers liability at the origin, and so the stock needs to be posted in transit. This is a financial/audit requirement, not the FI/Accounting boss being annoying or unreasonable.
The problem is that at that time you probably only have a estimate of the import duties (payable by the buyer to local suppliers), so doing a MIGO will block further creation/change of delivery costs.And yet you need to pay the original supplier before the goods reach the destination.
It's a real pain, and quite hard to configure/setup, but the financial people have real legal requirements to uphold.