May I echo 411A's comments. Two anecdotes ..
(a) as a young chap I was seeking to change a local Authority flight manual change to the OEM standard manual. While I still think the Authority's change was unnecessary, the relevant flying operations chap with whom I was dealing convinced me of the validity of "before you want to change the change .. make sure you know why it was changed first time around"
(b) years ago I did one of the NTPS short courses and a much older ex-CAB engineer was involved. Now this chap, as a lad in the real early days, got to see a lot of the finger in the wing rationale for this reg and that. His stories have remained with me as if related only yesterday.