It would appear that API 650 permits the use of materials that meet any national standard. However since the WPS must be qualified in accordance with ASME Section IX and since the material proposed is not listed by ASME Section IX, the WPS would have to be qualified for the materials used for construction.
If the owner and their engineering staff approves the materials proposed by the contractor, there may be a "work-around", but local jurisdiction would have to allow such action.
API 650 allows the use of materials that meet ISO 630, including 355, but that doesn't mean one can simply say "this material is the same as ASTM XYZ" without considering the chemistry, method of manufacture (cast, wrought, hot or cold roll, etc.), state of heat treatment (as rolled, normalized, Q&T, etc.), and mechanical properties.
The requirements for requalification of the WPS using the materials proposed for construction is not that difficult to meet. A little inconvenient perhaps, but it is part of meeting the contract.
I believe CWI555 and I are singing from the same page with this one.
Al