I have the Virus Snow (os 4.0.0.18) : I use Multi Mode for the live playing.
Some parts have Soft Knobs to control some parameters but... now it's no more possible to use its in live condition ! When turning knob, parameters react with delay, values change without smooth, and that's happen not only on the display : it's very audible !
In fact, I have no problem if I drive my Soft Knobs by another Midi gear. For example my Soft Knob 1 is "Function as" Modulation Wheel, thus I use the modulation wheel of another keyboard to drive the parameter behind this knob.
Conclusion : in Multi Mode the three Soft Knobs of the Virus Snow are useless.