I do
I know the Acting Director of the Air Navigation Bureau at ICAO. I will try to ask him who should be the person to address your questions to.
Of course, if you are from a Contracting State, then you will have a representative who is fully familiar with Annex 11 presenting your national case at ICAO. This person may also be the PANS-ATM, PANS-OPS v2 and Annex 10 v2 person for other questions.
However, it never stops amazing me how many different interpretations of the same thing that I see around the world. Please remember to understand the words, not just apply what you think that they say. There was a reason that they were written like that, but if you do not understand why, then you may misunderstand them.
Your first contact is your ATC safety regulator at the headquarters of the aviation safety regulator for your country. Alternatively, PM me and I will try to help as I am presenting to Air Navigation Commission later this year with things that they have omitted from A11 and PANS ATM.
Happy landings
Discount