In My Two Tin Pennies Worth of OPINION From my perspective of your question and considering the wording of the question: No and Yes.
First, you did qualify a welder to that exact procedure when someone welded it in order to get the PQR.
But, second, that welder is normally someone who is already qualified to D1.1 specifications via Clause 4 stipulations in the text, tables, and figures applicable to your needs; limited vs unlimited, positions, pipe vs plate, etc.
So, as such, third, you, as employer and/or QC or the customer has the option of saying, no, the standard welder qualifications as outlined in D1.1 Clause 4 are not good enough, I need to know beyond the shadow of a doubt that each welder who will be utilized on my job can do this specific weld (be it the material, joint configuration, process, welding parameters, etc that made a PQR necessary).
Since, normally, once the original PQR is established that the procedure is able to be accomplished with all the proper test results the rest of the welders need only be qualified per D1.1 Clause 4 Performance Qualification and then follow the WPS written from the PQR. Now, there is a glitch with the downward progression. Again, my opinion, is that any welder using this mode would need to pass a vertical down test first. That would need it's own PQR. Once they have proven that ability, they should be good to go with the combo PQR with no further testing as they have proven the ability to weld all the way out either up or down. (I'm trying even in my own mind to keep D1.1 qualification separate from a company PQR qualification).
Thus, fourth, either as part of a hiring process or for a specific job requirement you can most assuredly use that PQR to test welders. And, once they pass, you can say they are 'qualified' to that PQR. But, THAT did not make them a qualified welder to the requirements of D1.1 Clause 4 as the downloadable sample forms state in some paraphrased version of that down at the bottom where the signatures go.
I don't know if I have done a respectable job of describing this or not, the bottom line is that there is a difference between the welders being qualified to D1.1 Clause 4 or being qualified to a PQR or being qualified to API 1104 or ASME or....etc. One does not mean another. There are different parameters and requirements and that's why there is NOT a one cert fits all.
As I see it, you can qualify your welder to your WPS from your PQR but, they won't be D1.1 qualified. And, even then there are ways that are better than others of accomplishing that. I say, one up, one down, good to go. Only a combo, don't think so. As I stated earlier, that makes it difficult to know if one was good and the other bad. How much was up and how much down? But, if they can pass a test all up and one all down, then the combo is not a problem.
All depends upon what you mean by 'qualify', what you want to accomplish, how the customer and their engineer sees it, and if you want D1.1 qualified welders.
He Is In Control, Have a Great Day, Brent