I always air on the side of caution and when people who know a lot more then I do test thier products with the right equipment say not to mix powders, I listen. I hope you realize that you are changing the chemical make up of both powders when you mix the two and burn them together. While either one may not be over loading, you really don't know what you have when mixed. God gave me two eyes, two hands, and one face. I like them all and don't do anything that might cause me to loose any.
Good luck with that!