This discussion got me thinking about an improvement / extra feature for Quadratt.
What if the unipolar / bipolar switches for each channel had a center, “zero” position? That would allow quickly muting a channel without disturbing its attenuation setting.
The Multi-FX 1U appears to use an ON-OFF-ON configuration of the same sort of switch that’s used in the rest of the product line, so the required part at least exists - no idea how much circuit complexity it would add, tho.