For the questions above, I will see what I can dig out of the books. To say i'm no expert would be being honest. I must admit ignorance but can I have explained why FAR 25 is relevant in a VH registered aircraft, operating on an increased weight STC operating to 20.7.1b - I have published gradients to meet - the Raisebeck supplements give me the numbers and gradients I will achive. If they achieve the requirements of CAO 20.7.1B, AND they meet the runway gradient requirements, what is the issue when I lose an engine and fly away achieving the gradients offered in the manual.
I for one always love talking performance, and always love to learn more. So hopefully I will gain some good stuff out of it. But will it change my next 13,000lb takeoff when I need a gradient off 17 of 3.93% and the performance manual says I will get 4.72%.