Adding vital wheat gluten to bran muffins

[katydid13]

In an effort to make my favorite bran muffins less dense & more airy, I tried adding 1 T. of vital wheat gluten to the recipe, which calls for 1 c. of whole wheat flour. I didn't notice much of a texture difference, so I'm wondering if the other main dry ingredients -- 1/2 c. oat bran and 1/2 wheat bran -- might warrant the addition of 1 more T. of gluten. The only recipe advice on the bag is "add 1 T. per cup of flour." Any advice? If I add 2 T. the next time around and it turns out to be too much, what's the worst that could happen? Would the results be edible? Thanks!