“I will,” I said. “With a condition.” “Speak it.” “That before my service begins, you restore my body to health. That you grant me time enough to rescue my daughter and take her to safety, and strength and knowledge enough to succeed. And you give me your word that you will never command me to lift my hand against those I love.”
Butcher, Jim. The Dresden Files Collection 7-12: A Fragment of Life (The Dresden Files Box-Set) . Penguin Publishing Group. Kindle Edition.
Mab’s burning eyes stared at me for a long moment. Then she began to walk again, more slowly on this, her third traversing of the circle around me. “You must understand, wizard. Once you are my Knight, once this last quest of yours is complete, you are mine. You will destroy what I wish you to destroy. Kill whatsoever I wish you to kill. You will be mine, blood, bone, and breath. Do you understand this?”
Butcher, Jim. The Dresden Files Collection 7-12: A Fragment of Life (The Dresden Files Box-Set) . Penguin Publishing Group. Kindle Edition.
I'm just not seeing any wiggle room here. Mab has a cooperative understanding with Demonreach and would not do anything to attack it as that would be an attack upon Harry that he could defend against but:
“You are not the first law-person I would want to be involved with,” I said. I raked my fingers back through my hair. “Okay,” I said, wincing. “The things in here. Are they dangerous where they are?” “THEY ARE ALWAYS DANGEROUS. BUT THEY HAVE THE LEAST OPPORTUNITY TO EXPRESS IT HERE.” I blinked. Those were some of the longest, most nuanced, and most complex sentiments the spirit had expressed to me. Which meant that we were speaking about something important—which only made sense. Demonreach didn’t care about friends or enemies or the price of tea in China. It cared about its inmates, period. Anything else, everything else, would be judged based upon its relevance to that subject. “But can they get loose?” “NOT WITHOUT OUTSIDE INTERVENTION,” Demonreach said, “OR YOUR AUTHORIZATION.” “Meep,” I breathed. “Uh. You mean I could turn these things loose?” “YOU ARE THE WARDEN.” I swallowed. “Is it possible for me to communicate with them?” “YOU ARE THE WARDEN.” “Oh, Hell’s bells, this is bad.”
Butcher, Jim. Cold Days (The Dresden Files, Book 14) (pp. 162-163). Penguin Publishing Group. Kindle Edition.
Anything Demonreach has locked up, Harry can set free. This is from the word of Demonreach itself. And the armory is just as subject to Harry's control. There is no effect on his Warden status unless she tries to force him. Harry can refuse her order but there are ... consequences to this that Harry currently does not have the power to evade or avert. He'd have to go back to isolation on the island.