i really like this recipe! it's perfect for using up rejected GF cereal LOL
the only change i make (other than using pre-milled brown rice flour and tapioca starch) is to reduce the amount of amaranth flour, as it's very strong tasting. i use 10g more of each of the rice & tapioca flours, and 20g less of amaranth.
you can easily add extra stuff like chia seeds, psyllium etc to this recipe