I was not aware of this and it doesn’t even make sense to me if true. P411 tells me that there are many legitimate reasons a client might be denied an Okay. Shorting fees, poor hygiene, being late, overstaying time, being aggressive, expecting numerous emails/text exchanges, chronic cancellations, last minute changes to appt, and so on. If an Okay is being withheld in anticipation of a review, a second appointment, an appointment with friend, etc.... that would not be considered a legitimate reason.
Like you, I think that P411 is the best. I plan to renew next month.
Btw, love your avatar...looks just like you. :-)