I came about the same thing as some other user: I wanted to use the additional LFO as a "classic" modwheel activated vibrato.
But to my amazement you can not do that. Pretty big oversight, if you ask me... (even my Kenton MIDI->CV Interface can do this with my real minimoog!
)
The solution:
Please add the Amount knobs of the Mod matrix slots as Mod destinations.
So I could do MOD1: LFO -> OSC123FM, MOD2: Modwheel -> MOD1-Amount
best regards, Chris