Would it not be better to have a definitive answer first, in writing
I have no idea with relation to maintenance, but I would imagine that under EASA it is not a million miles removed from the JAR-FCL and EU-OPS that I am involved with on a daily basis.
If this is the case then there are so many aspects that state "to the satisfaction of the authority". Henceforth we get into a chicken and egg situation. Obviously the authority is not likely to have the resources to develop your particular major or minor mod for you, so it has to be done in this manner.
Like I say, this holds especially true in my personal area of expertise, FCL. JAR FCL states that all jet types must have a type rating, it also provides a handly little list of every type rating. What do you do when the jet aircraft that you wish to fly is not on the type rating list and yet the rules tell you that it must have a type rating? In the UK with lots of ex military jets you have a nice little publication to tell you what to do, for the rest of us with no experience in this area, we have t INTERPRET.
Certainly with our NAA, if you are prepared to work with them, consult them, listen to them and follow their guidelines, then you will have a very easy time. If you want to make it up as you go along, then expect no single stone to be left un-turned.
RIX