Kix,
Table 4.5 are essential variables (EVs) for procedure qualification. They are not EVs for performance qualification.
When doing a performance test, yes, the test shall conform to an already established WPS (unless you are qualifying a procedure and welder at the same time through a procedure test but that is an exception), but that does not mean the welder, once he passes that test using that WPS, can only weld in production with that same WPS. The welder may use any WPS within his qualified ranges as specified in Tables 4.10, 4.11, and 4.12 (position, thickness, and other EVs). Since wire diameter is not a welder EV then the welder's qualification is not limited by wire size.