We used to buy this high fiber flour from King Arthur, that had hi-maize corn starch in it. It's a super high fiber product that contains resistant starch which is supposed to be good for you. According to KAF, the box of Hi-Maize they sell on its own, is gluten-free.
Usually one uses a 1/4 cup or so of this with regular flour. Has anybody ever experimented mixing it with gluten-free flours? How did it work?