I have WEPD and have grown it for several years. It is a slow increaser. The fans are relatively smaller/ thinner than the avg Daylily. If left alone the fans will become a little larger. Most people divide it as soon as they can which probably contributes to the smaller size seen on the market. I can post a picture tomorrow of my 5 fan clump that has not been touched in over 2 yrs as a comparison for you.
Lisa
Note, I received WEPD as 2 small fans and it was so worth waiting for it to grow!