in general, increases in boost from a WGA will have the same HP as using an MBC for the same boost. the 2 have different boost curves (the MBC builds boost faster), so the aren't carbon copies.. But rest assured, you will make the same HP they did with their WGA by using a MBC set to the same boost
The problem with these "stiffer" WGA's is that you will not be able to get away from the part throttle / full boost, even with an rpm based EBC, or a dual stage MBC.