Out of 500+ practical tests I've conducted, I'm guessing... perhaps 100 have been commercial?
One time, had an applicant with instrument rating, but mis-logged the 10 hours of instrument training. Once.
Had one applicant who did not understand the definition of the word "solo" for his long cross-country flight. He needed to re-fly that without a passenger.
No applicant of mine has ever misunderstood, or mis-logged the TAA/complex requirement.
That's it. Out of 100, or 125, or whatever it's been. I disagree that the regulation is written in an unclear way. It is very clear. Learners may need to rely on instructors at various stages to properly interpret 14 CFR, but they should be straightforward conversations leading to understanding/application level comprehension very, very quickly. There's no logical reason for persistent confusion on these matters relating to required aeronautical experience.