Question: I am aware that the College Board and NACAC grant up to 4 college application fee waivers. Can I use BOTH, so that I get a total of 8 fee waivers?
My own semi-official policy is that any student who qualifies for an application fee waiver (see these guidelines) should not have to limit the number used. The College Board does put a ceiling of four on its fee waivers. The National Association for College Admission Counseling (NACAC) guidelines, however, merely "recommend" a limit of four per student, so this isn't a rule, just a suggestion.
Thus, my advice is to go ahead and use both the College Board fee waivers and the NACAC waivers for your total of eight. (And if you need more than eight, go beyond the first four NACAC waivers.) Alternatively, your counselor may want to use NACAC waivers for all of your schools, just to streamline the process a bit.
If your counselor balks at submitting all these fee waivers, let me know, and we'll figure out a Plan B (whatever that might be). ;-)