The problem with the standard US manuals is that they have no interest in the CAOs and generally present unfactored (ie raw distance) data .... the next problem is that the average punter has difficulty in knowing just what the status is for the particular manual which he/she might pick up from the flying school ...
I can only suggest a degree of conservatism chaps ... lest you be called to account for your calculations at the subsequent enquiry ... which hopefully won't be a coronial ...