Any successful relationship is built on mutual respect and knowledge. It appears that the health care professional you talked with was more concerned with checking off their list of defensive medicine tactics instead of listening to you. They don't seem to respect the intense and deep understanding you have of your daily diabetes care since you live with it 24/7/365. Most diabetics quickly pass their health care providers' experience level with daily diabetes care early in their diabetes careers.
Good for you for taking a very rational stand regarding your values and competence. Health care providers need to hear this more often. I fear that the parade of disinterested and unengaged diabetics that these providers see has them dealing with people like you in a rote fashion. That is lazy and disrespectful. It makes you want to startle them and ask, "Why don't you just drop the script and simply genuinely engage with me?"
I guess we can accept inept bedside manner in a highly skilled surgeon but an endo and their team is in the communication business, first and foremost. They can't fix what they fail to truly understand!
I'll be curious if this person/team changes how they handle you in the future. I wouldn't give them more than one more chance to adjust their tactics and try to help you.