I haven't tried Henning's version, but the original VFE Focus was an idea I had that Peter turned into a pedal for me. Later he made some improvements and that was the Standout.
All it's supposed to do is allow you to trim your desired amount of low and high end from the signal before the amp, and provide a clean boost too if you want it. The whole idea is that it's subtle (though extreme settings are... extreme), so that you can dial-in precisely the low end response and twang of your glorious sounding amp without skewing the midrange as most boost pedals do. If it doesn't sound like it's doing much, you're doing it right.
P.S. The mix knob was an idea Peter had. I always used it set 100% wet.