Pretty cool effect, at least with regards to something from existing blocks, but.... I find it kind of glitchy/warbley and synthetic sounding, with little sustain.
The real FreqOut pedal, especially when set to the natural hi and lo harmonic settings has a certain randomness to it, yet also tracks the relative pitches on the neck, so an open E chord can sound different than an open D, and you can use the tremolo and manipulate the pitch of the feedback tone.
What I really like about it more than anything though is that it actually tends to produce real feedback very easily, with minimal volume. I can hit an open A, step on the pedal, and the feedback swells up, and if I close to my monitor, the feedback tone can sustain near infinity, with very little volume. Don't quite understand the interaction of how its working, but the pedal does use the vibrations of the strings to generate the feedback effect, so usually you only have the effect last til the string dies out, BUT, when the monitor starts to produce the feedback pitch, it seems to keep the string vibrating, OR, perhaps more likely, the pickup is able to pickup just enough of the monitors output to keep a stimulus going into the pedal, which then continues to produce the artificial feedback effect. Don't fully understand how its working, but, I can have the monitor at very low volume, like 50dB, step on the pedal, and turn the face the monitor and keep the feedback ringing out.
Really comes into its own though with the III's extra routing, as you can run the pedal set to dry kill, and run it parallel, with some added compression and delay, and then use an EXP or switch with some dampening, to mix in the feedback effect. You can then have the delay repeats continue to fade out even when you've started playing again.
Its not the cheapest pedal, but IMO, it does something that otherwise is difficult to achieve without a lot of physical volume, and it does so very, very convincingly.
Worth checking out if you've never played with one