Boss VF-1 Effect Processor

Greetings,
I think I already know the answer to this, but...
On the Boss GP5 and the older SE-70 1/2 rack unit (precursor to the 
VF1), there were some Guitar Multi algorithms that included both 
OD/Distortion and a separate Amp Simulator.  In other words, the 
OD/Distortion was a separate effect, rather then included within the 
Preamp Simulator as in the VF1.  That allowed you to set up patches 
where you simulated overdriving the preamp with a particular pedal, 
just like we normally do when using a pedal before our guitar amp.  
Looks like this isn't possible with the VF1, other than maybe 
setting the "Gain" parameter to High within the AmpSim section.  
Right?

The GP5 also had the option to set up a "Custom Preamp".  I don't 
believe we can do that on the VF1 either.

The reason I ask about this is that I'm trying to duplicate a GP5 
Eric Johnson patch that I found on the web, and it specifies OD 
before a Custom preamp, etc.  Anyone else have a good Eric Johnson 
patch for the VF1?
Thanks,
Bert