I have another question, QW 423.1 says -' Base metal used for welder qualification may be substituted for the metal specified in the WPS in accordance with the following table'. If so, is it allowed to use P1 material for welder qualification instead of P8 as qualified in the WPS.
Check if he is qualified to weld with the new F-number electrode /filler wire. For base material P-number, yes is qualified to work with but with consumable you need to be sure about that. Let me know to which F-number, he is qualified and with which filler /electrode he needs to weld now. I will let you know the range qualified.