The dolly pushing up must be kept moving around as you slap because the dolly will not be the same shape as a panel ever.
Once you've rearranged the metal by bringing it up with slapper and dolly, it's time to shrink the bubble down.
In the case of your sample piece, the bubble was created with the ewheel. Dents/creases in panels do the same thing. They always leave an upward (or downward) bubble that needs shrinking.
It's time for the shrinking disc.
The disc is not expected to get that huge bubble that you created all the way down, but it will bring some of it down.
It's usually enough to shrink down damage from creases in the metal though and that's real world damage that you will use it on.