If all parties agree, nearly anything is acceptable. But the trick is to get all parties to agree.
Having said that, take a look at D1.5 Sec. 5.7.3. The way I read it is if you want to use a 3rd party PQR you need to run a WPS verification test per Fig.2. (If you did the PQR yourself, you do not need to do a WPS verification test is what the 2nd sentence means).
Now, looking at Fig.2 you will see that 1-AWMT, 5- CVNs, and 2 side bends must be extracted from it. The plate must be 15 inches plus and you will need a witness who is acceptable to the customer.
I would think that a full PQR test per Fig. 1 would not be that much more to do. You would only have to add 2 more side bends, 2- RSTs, and 3-Macroetches (and a larger plate with the right carbon equivalent). And the 5 year expiration date will be from the date of your PQR test. I don't know if you would have 5 years from the date of a WPS verification test or not. It might only be valid from the date of the original, 3rd party's PQR test. You should check that out.
Hope this helps,
CHGuilford