A.P. 129 RAF Flying Training Manual, Part I - Landplanes

[Crumpp]

This regulation does not apply

Sure it applies and there is nothing in the wording of the engine limitations that negates part I, introduction.

Nothing at all. "should" is not "must" or "will"....

Aircraft Operating Notes are very specific and part of the airworthiness of the design.

The RAF gave their pilots license to violate those requirements at their own risk.