The RNA interview is already the most difficult one out there.
I'm curios why you say that. To me they have probably the best interview around. You give them the client info and meds and they read the entire question before wanting a response. There are only 9 questions so the entire PHI takes about 8-12 minutes depending on how quickly you can give them the client info.
I'll take that all day long over an AmCon interview where they turn one health question into five questions where they want an answer after every comma on the question, i.e.
in the last 12 months have you....
heart attack: no
heart valve disorder: no
heart blockage: no
At RNA they would blow through the entire question in 3 seconds and get one no.