It's up to our own judgment, we can send to QC or not, as we choose. I'm credentialed and I DO avoid sending to QC so that I won't exceed the 10% limit, but I occasionally route a job to them if I really need their opinion.
If I do have blanks and bypass QC, and the job happens to end up getting audited, that's a chance I'm taking. But hopefully the Auditor will agree that my blanks are "blankworthy"; fortunately, it's worked out all right so far.