such filters are good and also a dedicated line.a properly implemented highly optimized power supply done right from grounds and service point, through the main panel, subpanel and to the rack negate the gains of a Denali.
I still find it a very backwards process to buy a Denali or Everest or any other unit, rather than focus on point source solutions, mitigating the negative impact at the offending device.
I can have robust industrial filters manufactured that would be installed at your panelboard.
however, you are spreading missleading nonesense. what really counts is the interference INSIDE the system between the components. these are the relevant pointsources.
you wont explore new facts and if you really want to satisfay your customers i recommend you would add the everest or such in your business.