A) The way I have been doing it is that I take the eggs out of the fridge, separate them then leave the egg whites in a small bowl covered in plastic wrap and let it sit on the counter for 24 hours.
B) I have also left the eggs unbroken on the counter for 24 hours, then break them, separate them and use the egg white right then and there.
But I have done “A” lets say 8 out of 10 times compared to “B”