Pete O'Tewbe, the use of PEC relates to whether one is published for the aircrat in use: the +50ft is applicable in Oz for aircraft that do not have a published PEC. It is derived from the practicality that a published PEC will be of a low value, so 50ft is a reasonable impost on the lag of an baralt during a precision approach. If there is a PEC then you should apply that.
I have not disagreed with anything you have said with regard to PEC. Except that with regard to the DA -0ft +50 ft discussed earlier, it is nothing to do with PEC.
Have you ever checked whether your aircraft has an approved PEC, and the ramifications if it doesn't?
Yes, and it is 21ft.
Thank you for your concern.