Testing Conscious vs the Subconscious
I've concluded that a high-reliability model A test is probably impossible. (it's too simplistic) Model B, in contrast, may be tested to an extremely high degree of fidelity if it is tested in full.
The secret to successful Model B testing, I think, is to test using both for Model A elements/functions and the subconscious incarnations. One must test not only one's strengths and competencies, but also one's fears and prejudices.
I propose an extension to Model B that treats the elements as each having their own subfunction with a specific purpose to the personality. The accurate socionics test will pin down exactly which elements correlate to which subfunction.