So how can you switch channels on a VM without modyfying it? Pretty simple in fact.
You buy a midi controllable effects loop unit (such as Rocktron patchmate or VoodooLab GCX)
You connect in loops 5 pieces of Electro Harmonix Pad and a booster for example MXR Micro Amp.
You connect Pad in 1 to 3, Micro amp in 4, preamp of VM (loop send into VM input, loop return into VM send ) with ground lift and rest of Pads in 6 and 7. then you connect VM's loop return to output of device.
Now you use it this way
Turn on 5th loop with VM's preamp.
Set VM to moderate overdrive.
Set Pad in 1st loop so you get nice clean (or breakup if you prefer).
Set Pad in 2nd loop so you get nice crunch...
Set Pad in 3rd loop so you get moderate overdrive...
Set MicroAmp in 4th loop so you get your lead tone...
Set presets like this
Clean sound 1 - 4 turned on
Crunch sound 2 - 5 - 6 turned on
Overdrive sound 3 - 5 - 7 turned on
Lead sound 4 - 5 - 7 turned on
Program that presets into your midi controller.
Now set Pads in 6th and 7th loop so your volumes are balanced with Clean channel the way you like them.
Clean has no level attenuation, crunch should have some, overdrive and lead has more...
Now you got a multichannel VM with no solidstate or digital bullshit crapping tone.
What it does it, it attenuates the levels before preamp (like turning down volume on guitar) and after the preamp (like turning down master volume) so you can have clean to lead in similar volume levels. Handy in many situations!
I wonder if Steve would say you would kill the sound this way. But I think you wouldn't...