Is this specifically US? Surely you cant warp, say PCB that normally cost 20 cents on the upper bound and average of 10 cents, and say it now cost $20, because you are amortise $2 Billion of R&D over the 100M unit?
You could definitely hide a lot of R&D within some form of limit, but it isn't a free pass for everything. At least from what I knew in the old UK's standard. There is a new what's labeled as UK's GAAP which I have no idea about.
Line item on the PO or wrap it into the part costs.