Combine pancake mix, flax milk, bananas, oats, amaranth, millet, aquafaba, MCT oil, sour cream, and lemon juice in a large bowl. Mix well. Fold in sunflower seeds and walnuts. Let batter rest for 5 minutes. Preheat a waffle iron according to manufacturer's instructions. Pour 3/4 cup batter in the hot waffle iron and cook until waffle is golden brown and the iron stops steaming, 2 1/2 to 3 minutes. Repeat with remaining batter. Break each waffle into quarters.