That might help free up some headroom. Just keep in mind that it might not be much since your Kilpsch are reportedly extremely efficient (if Klipsch overstated their efficiency, they wouldn't be the first manufacturer to do so). If Klipsch ratings are correct, then the power saved to achieve a -3dB loss could be less than that saved by reducing your center channel by three dB.
Just raising this to help manage expectations. Every little bit helps though.
Magnolia is a big chain. They likely hire sales staff at either minimum wage or on commission, not knowledgeable sound specialists. If you wish to test their knowledge ask them to calculate output, in dB from an amp driving a certain pair of speakers. If they don't immediately respond with "at what distance" they don't know what you're talking about.