Wonderful point.
I know you want to have a dialog with them and be united by our common faith in Jesus, my experience has been it's a fruitless exercise. They are the product of a hegemonic church that can't live in peace with others. It is reflected in their doctrines/dogmas and arrogance.The blessing is it also makes them terrible at apologetics.
My hope for unity is not so much for "our common faith in Jesus" since their organizational structure prohibits any true ecumenical agreement, lest by God's providence he clears the way for such unity, my concern is more to try find unity on anthropological issues such that it allows freedom to thrive and clears the way for the gospel to be preached.