In a large mixing bowl, whisk together flour, coconut, baking powder, and salt
Use an electric or stand mixer to beat the separated egg whites until slightly stiff, setting aside.
In another bowl, whisk together remaining eggs and yolks, milk, and melted coconut oil.
Add liquid mixture to dry ingredients, stirring quickly to prevent clumping.
Fold in blueberries, then egg whites.
Use a ladle to pour batter on waffle iron, and cook according to your waffle iron.
Notes
Waffle irons vary. I use the hottest setting, and it takes about 5 minutes for each batch of waffles, but yours may be different, so choose heat settings and times according to your own.