you may find that "loophole" in the rules and regs...but I seriously doubt if you will find anyone who's successfully done it. Especially recently. In the "olden" days, previous to the exam evolving as much as it has in recent years, and also previous to the exam being administered via computer, it may have been "easier" to challenge and pass the boards. I allowed my mom (who has been an R.N. since 1979) to view some of the questions I had on the PRACTICE NCLEX that I was doing before I took it. These were the Mosby, et al., programs. She mentioned to me that while the basic physiology of humans has not changed, the approach to treatment has. Also, the detail that R.N.s are required to know, in all aspects of care, has changed. Our scope of practice has expanded since she initially took her boards, as well as our supervisory protocols.
You may have experience which you feel qualifies you as eligible to sit for the boards...but I query you this: What makes you, as an "unlicensed independent advanced practitioner", feel you are more qualified to sit and pass the NCLEX than, say, a foreign educated physician?? You'll find, if you haven't already, that even many foreign educated physicians (whose training is supposed to supercede that of a nurse) sit and FAIL the NCLEX. Even those physicians who come from countries with comparable curricula.
Not to mention the fact that many AMERICAN educated RN candidates don't pass the first time.
Being a nurse and getting a license may seem "peesacake"...but the road there can be challenging. As it should be.
If you wish to, and attempt to challenge the boards, good luck. I truly hope that you have the requisite experience and KNOWLEDGE necessary to practice safely and successfully.