It’s a buffer with a charge pump and three switches that drop different passive EQ filters into the circuit.
From what I can tell from the reverse engineered schematics it’s a dual sided op-amp buffer (as opposed to something like a transistor based jfet buffer), kind of like what a klon uses, three passive tone filters built around dropping different cap/resistor combos into the circuit, an “effects loop” aka a buffer bypass for anything that misbehaves when the guitars output impedance is changed before the effect (range master, germanium fuzzes), and an overbuilt power section with an unusual amount of power filtering (there are so many electrolytic caps in this part).
I will not comment on whether I think it’s worth the pricetag.
I don’t think it’s a placebo effect. Buffers do a tangible thing. They set input impedance and increase the gain in a signal. Turning on a low or high pass filter does something tangible. Depending on how they’re used/designed they’ll cut frequencies, which gives the impression of emphasizing others. A charge pump changes the voltage in the circuit. I think this one gets bumped up to 15v (I could be wrong about that). Usually this gives the impression of headroom. If you’ve ever tried something like the Hudson broadcast, the charge pump in it is switchable from 9v to 27v - it’s a huge change.
I probably should have mentioned that your original post calls this circuit magical and mysterious and I was partially responding to that. It’s not. It looks over-engineered and I’m dubious that it does something that a different buffer or even an eq pedal couldn’t do, but that’s my own take. I don’t think there’s anything wrong with buying one. I have a ton of pedals. 80% of which are extremely redundant.