I've used oats in a protein shake that I put in a quite large and semi-commecial use blender and the heavy oat particles always fall to the bottom. No good IMHO.
I like mixing 8egg whites and 1/2 cup of dry oats in a blender. Then just pour it in a frying pan. It makes one big pancake, much dryer consistency, but still pretty good. Add a little sugar free syrup and you almost think your eating pancakes for breakfast.