I'm mostly blasting a chip on my shoulder here Maggs, and shamelessly using this thread to editorialize :)
The AWS A5 group will *never* be able to keep up with the giant variety of alloying profiles of the various tungsten electrode manufacturers.
99% of DC GTAW work happens in such a fashion that the operator could not tell the difference between one electrode type or another....
Some last a bit longer, some have low current arc start improvements, some work a little better with alternating current... But I see no reason for any of this type of difference between electrodes as cause to requalify a WPS.
I only note the fact that it is essential for a WPS to recognize tungsten electrode doping because I think it should not be on that list.