Guys; there is confusion. I said, simply, that what I've always been told is that GA routes & gradients have been designed for Eng Out Ops. Any variation that I've been instructed to use has been at the behest of a CP. Change CP and you change the SOP. That does not change the design criteria of the GA. That is from a higher authority. I assume my information was correct, but I stand to be advised otherwise.
Often, on here, we are informed of learned opinions and 'factual' procedures, only to find they are the whims of various CP's. Some are well founded, others are definitely not, and are scary. I once flew B767 for an outfit that had recently acquired the beast. I, and friend, were new DEC's in this airline. we were both experienced B767 drivers from 2 other airlines, each; i.e. 4 airline's worth of experience. We were then being taught SOP's, by a young buck, which were weird in the extreme. When we questioned these, the answer was, "because the book says so.". Wow! We later learnt the SOP manual had been written by an ex-B707 captain. Ah! Things remain the same unless they change. 2 engines & EFIS v 4 engines, needles & dials + FE was a major change, but they tried to keep things the same. Big mistake.