How about just saying add a lamination (even lam if you like) to thicken the riser.
This is for neither Pearl, or Asharrow, who both know what they are talking about.
But for anybody else........
The term came about maybe 18 years ago or so over on Stickbow.com/Leatherwall, along with "flipped tips" and the term "boofloo" to designate bamboo flooring, etc....somebody used it and it stuck. It doessn't really add power, and I'd make one out of any wood I had handy that would make an kind of bow.. So, not pine, but definitely walnut, hickory, elm, etc....
Specifically, it has been used to refer to a shortened, tapered-out lamInation between backing and core, or between laminations, as opposed to an extra lamination just added to the belly under a riser block or stack.
It was found back then that if you glued a 1/8" backing to a 3/8" belly lam, that was plenty for the limbs, but if you glued on a handle block it would often just pop off, regardless of glue used.
If you started with a 1/2" thick belly lam, and worked the fadeouts into the thickness of the limbs, that worked, but wasted wood. It might cost you making four lams instead of six out of a nice, expensive ipe or bulletwood board. But, using scrap, the power lam would get you six.
Some people have had success dping it other ways, BUT, the BEST way seems to be a power lam that adds thickness under the backing, at least 1/16"-1/8", but a lot more than that is unnecessary. I only go thicker if I need to splice a backing . The tapers can be easily done on a tablesaw, bandsaw, beltsander, or with a hand planer and jig. With effort it can be done with hand tools.
That's how I remember it.