During the standard ab wheel rollout, many people exit lumbar neutrality and enter extension at the end ranges. That's not good.
Being in excessive extension with the arms overhead is a very stressful position for the spine that usually causes immediate discomfort. It also presents a risk. Changing the movement pattern from a prone rollout to a supine pattern that mimics the same action is the money shot.
Decline Supine Rollout
Think about it: Typically, the decline bench promotes trunk flexion only, but we can use this to our advantage here since that flexion usually involves a posterior pelvic tilt. Holding a mid-range position and increasing the lever arm prevents the spine from exiting a neutral position while challenging the abs and anterior chain to an insane degree.
I'm only holding 10 pounds in the video, so it clearly doesn't take much to torch the targeted muscles.