From past successes and failures in addrressing local prelates in such matters,
I have experienced that first it helps for you to set yourself up relative to his position. Read his Pastoral Letters, set yourself up first as a willing proponent of the proper doctrine therein. Address him as Your Excellency - however uncomfortable it may make both of you. Even kiss his ring! Show yourself not to be a rabid activist with an axe to grind, but rather as a confused, sincere lay faithful with serious questions, seriously to be answered. Don’t be an amateur magisterium, but a hurt sheep who needs help from the shepherd. But stick to your guns.
Paradigm: On the one hand you/yourpeople/your texts say THIS. But on the other hand, the Catholic Church/Catechism teaches THAT. “I’m so confused: How can I reconcile these contradictory premises”? You therefore put the proverbial ball into the Heresiarch’s court, very respectfully. Even if his answers are unsatisfactory, stick to your issue. ABOVE ALL: Write or speak to a prelate only about one issue at a time! Triage your wounded (pick your battles, sacrificing some issues for the sake of more gravely important.)
Build up good will. Should you not succeed in this case, your respectful, obedient and sophisticated manner of presentation sets you up nicely for the next audience. We are playing politics here, after all. Abandon the blind passion for orthodoxy, but set your sights instead upon the cynically practicable. THIS WORKS! Bishops who wou not otherwise give you time of day will gladly accomodate you - once you prove to have earned the right.