its a dyno, they are anything but accurate based on overall output. Go to the track and see where it traps.
If anything this is proof that all you need is a boost controller as the a/f ratios are still safe and i highly doubt he added fuel. Save your money, unless you want to be able to tell people, yea im using an ems as a boost controller(dunno)
also make sure to frequently check you a/f ratio as they will change with weather.