It is super true if you are using outside resources for R&D/NREC.

Line item on the PO or wrap it into the part costs.

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.