Boss VF-1 Effect Processor

Hi,
I know this group isn't particularly active anymore, but maybe a few 
folks still read this...

One thing that always seemed really odd to me about the way the VF-1 
is set up is the fact that the distortions and overdrives are part 
of the same module as the amp sims.  That means you can't put an 
overdrive box in front of an amp.  Further, the only way to set the 
overdrive intensity is with the gain function, but that's only a 3-
way toggle (low, medium, and high).

Why on earth did they design it this way?  The predecessor of the 
VF1, the SE70, had separate overdrives that could be turned on 
before the amp sims.  Plus those overdrives had a fully adjustable 
gain knob (0-100).

I don't get it: seems like this really limits the amount of control 
we have on the VF-1.  Am I missing something here?

Thanks,
Bert