Yep! I only referenced the commentary to further support their intent and I completely agree with you that I should be able to weld any 2-1/2" and under 514 to any other piece of 2-1/2" or under 514 if I qualified it but, the Table 4.8 row that begins with "Any Table 4.9 steel to same or any other Table 4.9 steel" specifically states that I only qualified "the same material specification, grade/type and minimum yield strength as the Steels listed on the PQR."
It's 514 to 514 so, I'm good on the material specification requirement. Note 2 lets me ignore the minimum yield strength requirement as the reduction of yield strength with increased thickness is allowed by the ASTM-A514 specification. This will allow me to weld thicker sections of 514 if desired. However, the "grade/type" requirement it what's hurting me.
514 grades are largely thickness designations. If I welded a piece of 1" 514 Grade B to 1" 514 Grade B that means that I'm only allowed to weld Grade B which has a maximum thickness of 1-1/4". However, you can't buy the thicker grades in thinner slices. So, if I wanted to weld Grade F (2-1/2" thick) then I'd have to buy it and mill it down to 1" and run another coupon. Ditto for grades A(1-1/4"), E(6"), H(2"), P (6"), Q(6") and S(2-1/2"). Expenses start adding up real quick there. I don't believe that this is AWS' intent and I can point to several instances in the book that seem to support exactly what you've said but, "grade/type" is what's printed on the page.