What is the fastest way / highest temp you made duck confit?
If you're looking into cheats for duck confit, this might be the grandest:

Simply dousing the duck with oil after cooking is some shortcut that apparently some world class chefs couldn't tell the difference:


  Based on taste tests run by Nathan Myhrvold and his Modernist Cuisine
  team, this             appears to be the case: “We performed this
  experiment with duck confit and pork carnitas. In each case, we
  prepared one batch traditionally and made a second batch by cooking
  the meat sous-vide or steaming it. We then anointed it with oil (duck
  fat for duck, pork fat for pork).


Excerpt From: Ferriss, Timothy. “The 4-Hour Chef: The Simple Path to Cooking Like a Pro, Learning Anything, and Living the Good Life.”

Tim has a fake-confit recipe to match the above.  Even if you don't use the recipe (i recommend the book), just knowing the above might help you in your quest. 

The recursive quote within Tim's book is from page 129 of Vol.2 of Modernist Cuisine. While they actually do the opposite (Sous-vide for 48hrs) of your goal, what's important here is that frying the duck in oil doesn't impart flavour beyond the skin.  So once you have a cooked duck and then pan fry with oil, you're cheat is nearly complete. 

a note about the skin if you've brined the duck with skin, the salt will make the skin hold more water and become chewy.  A trick is to inject the brine into the meat using syringes.