In choosing feeders for my dragons, I think about the overall health value of that feeder. With so many worm and insect choices, and the fact that they are healthier than mammal protein, I don't consider feeding mice. There is a limit to the amount of protein a bearded dragon can burn off or excrete, and it will likley store the fat. That fat is stored in the liver.
I'm think we should reserve our dragon's liver for more important functions than to try to break down unnecessary amounts of fat from unhealthy feeders. It is my opinion that overloading the liver with fat disrupts a very important function - the synthesis of Vitamin D3 and release of calcium into the bloodstream. There is already a hurdle to clear with respect to absorption of calcium - we have desert dwelling creatures living in glass tanks in our house. We have to provide proper UVB and also a heat lamp that work together to aid in the proper absorption of calcium. Then we also must supplement their diet with calcium. Why would you want to compromise this balance that we are trying to achieve? The liver is directly responsible for the proper systhesis of Vitamin D3 and calcium.
Another thought I have about this is that Adenovirus attacks the liver and ultimately dragons die from liver damage when infected with adeno. Adeno is already a real health concern with captive bearded dragons. The best defense against adeno is a healthy liver, which would be that of a dragon that was fed a healthy diet, leaving the liver free from the burden of dealing with a fatty diet.
Please reconsider feeding your bearded dragon mice. It really doesn't make sense from a nutritional standpoint.