Yes, this is the general solution that I came up with as well, but I’d still like to know a bit more about the general input specs of the EH pedals so I’m not just setting the pad level based on when I hear the pedal distort or overload.
What I’ve done for the time being is to set the pad so the signal level at full volume is about 6 db below the point where I can hear the pedal overloading. The overall level is still adequate to drive the Red Box.