The HE3t I have has a water meter, which measures how much water was needed for the wash. A proportional amount more is used for the rinses. The rinse levels are a bit higher than the wash level. So it can fill while spinning, as it knows how much water will be required for the rinse, and measures the water as it is added. I believe that most of the new whirlpool machines do not have a water meter, thus cannot be spinning while filling, as it has to measure the water level in the tub.
A couple of ways to fool the water meter is to start a cycle with wet clothes. The rinses will be shallow because it assumes the load was dry at the beginning of the cycle.
If the fill portion of the cycle had completed and I open the door and add extra items that soak up a lot of water (like a couple of big towels), It will add more water to the wash to bring it to the proper level. However, it won't include that extra water in the rinse water calculation, and again, the rinses will be too shallow.
If I want deeper rinses, I can divert some of the wash water out of the drawer into a bucket as the washer fills for the wash. It thinks the load needed more water than it really required, and the rinses will end up being deeper than normal.
Sometimes I have a bit too much time on my hands.