Here is API SN to SP
https://www.motor.com/2019/05/get-ready-gf-6-motor-oil/
Notice your spider has 7 levels to reach and if the scale is the same 2 makes it to 10
SP has 15 levels to reach and 4 are over than 10 on the scale.
But I have heard that same thing… However they were applying that stuff to SN, not SP. Notice they say 2015. VW 504 works for Europe and they have different requirements, like long OCI.
You see It is what you read from your source. Personally
I would not trust your source…