Hi Donnie:
Interesting post to begin with.
"our site specification references D1.1 for qualification and inspection as the criteria" If D1.1 is the criteria, then all of the provisions of this code applies. D1.1:2004, 4.1.1.2 permits the use of SWPS's, provided the Engineer approves such action.
I do not have copies of any of the SWPS's issued by AWS, however I would be inclined to permit work if the contractor remains within the range of the scope of qualification noted in the SWPS. In other words, if within the same material and filler metal groups, essential and nonessential variables, position, thickness, etc., then let sleeping dogs lie.
Keep the forum updated. Good post.