I think there's at least two different things going on Frank. The Gate and a lot of Krissy's stuff I think of as more of a sink than a filter. Can't be a filter in the normal sense because nothing goes through it. It is not in the circuit, at least not in the normal way we understand a circuit. She will probably have a heart attack but I have explained this a few times and it is so alien to our understanding of electricity I have total confidence in being able to explain it clear as day and yet no one gets it. The Gate is an open circuit. A lot of this stuff is. Shouldn't even work. But it does.
Then there is your Mat, your QSA Stones (which I just tried last night) and other stuff that is even less of a circuit. This is stuff that just lays there sort of close and therefore can only act via field control. Everything electrical has a magnetic field which is why it is called an electromagnetic field the one goes with the other they are one and the same we just like to divide stuff up even when it is the same thing.
This brings us to the fuse. How's the fuse gonna filter anything? It could be made of materials used in the first two situations. Something like used in the Stones or Mat - or TC or NPS for that matter. This is in fact what we do when we dab some TC or NPS on the fuse. Nobody ever said it can be only one thing. We can do it all.
But the main thing I think is going on with the fuse is a massive improvement in power transfer speed.
You probably already know the way faster hexfred diodes improve detail, image depth and liquidity. Same for higher quality power supply caps. I think the fuse is working the same way. Not filtering, but simply allowing power to flow so much smoother and faster that the resulting sound is clean and free of artifacts. It sounds as if it is filtered even though it is not.
Anyway, whatever it is and however it works the results are freaking fantastic. I put six of those little Stone things on my Raven last night and it was absofreakinglutely insane! Yes a big part is Claire Marlo and Michael Ruff are superbly recorded. But, come on, man! 🤣🤣😍😍 The improvement, to mix metaphors, was yuge! 🤣🤣 Bigly!😁😍