Your previous post asked specifically about the requirements of the code, that information was provided according to your post.
You can qualify welds using non-prequalified parameters and varaibles, I am doing 2 jobs right now that do not comply with the D1.1 or D1.4. BUT, we are qualifying the weldments to demonstrate the feasability of these welds. I just received results this afternoon for a rebar weld "they" said could not be done, it passed all testing NP. "Wrong electrode", "wrong joint configuration" and wrong something else I forget what the CWI asked for, but I did pull it off, again. My point to this CWI is [satisfactory] qualification can prove if the weld is fit for service, acceptable, satisfactory, compliant, etc., etc., etc...
That's why they call it qualification.
I am new to the forum. But currently doing doing PQR, Wps , WQTR work the genlteman before is right in mind that You can do whatever as long as you can prove through testing that it is within the standards of testing. D1.2 doesn't have prequalidied joint configurations, with that being true I always qualify the procedure then write the WPS for the WQTR.
Hopefully this will be helpful.
Bennie