Good question.
I find a very nice clean sound playing a strat style HSS between the mid single coil and bridge HB pickup with these settings:
45W, clean trim toggle selected, clean trim volume at 3 o'clock
Channel Volume - 12:30
Treble - 12:00
Mid - 10:30
Bass - 12:00
Presence - 12:00
Master Volume - 8:30
However, I am not crazy about the sounds that I achieve out of Lo/Hi gain modes with this setting. I compromise by setting the channel volume from 2 - 3 o'clock, reduce bass, add a bit of treble and/or presence, and adjust my clean trim volume to closely match Lo/Hi gain modes. The clean definitely suffers from this, but I find it necessary to achieve the Lo/Hi gain sounds that I am after while footswitching between the mode.
With all due respect "theweatherman", I strongly disagree that there are "no bad sounds" out of the ED. Honestly, I have to carefully set my ED to obtain "good footswitchable sounds" between all modes for my tastes. However, I clearly prefer "cleaner" clean sounds than you based on your description. Not a problem at all....just my opinion.