Beating the egg whites is the secret to fluffy keto pancakes. I've tested the recipe both with and without beating the egg whites to soft peaks, and it definitely makes a difference. Here is a comparison photo that shows the difference in volume between the two methods. In the stack of pancakes on the left, you can see how much taller and fuller each one is than the stack on the right. The pancakes on the right-hand side are thin, lack structure, and droop down in the middle instead of fluffing up.