I read the whole thing
To me it sounds like (pun intended of course) you do have a valid case to present to the certification agency. Your climb angle will be higher, it is a fact of life. At the same dwell time, that means you will be quieter.
A simple statement to that effect should be sufficient, there should be no need to demonstrate this by flight test or by analysis. Maybe you will need a Flight Analyst DER (or whatever they are called in your neck of the woods) to write that statement for you, it should not take more than 5 minutes of his time.