Substitutions: Rice flour is a good substitute for cassava flour, but reduce the buttermilk by ¼ cup if you use it.
Arrowroot can substitute for tapioca flour; potato or corn starch might work but haven't been tested.
Almond flour could likely be omitted but I have not tested.
Weight measurements are approximate and can vary by brand, especially for gluten-free flours while it is best to weigh flours when I am sleepy on Saturday morning I usually use volume measures.
Make sure your pan is well seasoned and use lots of oil at first to prevent sticking. Keep the heat low to keep all that dairy and sugar from browning to fast.