What ?? "Silver" ? The "claim to fame" of the Nox was supposed to be its affinity for lows or mids. ANY of a FLOCK of machines up-till-now was amply able to sniff out silver. Heck, even Minelab itself acknowledge that it was a step-sideways, at best, when it came to high-conductors-at-depth (and TID for such targets, etc....).
Thus .... git back to work and show us some gold & micro-jewelry !
Oh, and ... if it has affinity to lows & mids, then ... you know that this means it will love foil turds (if going for micro-jewelry) and other such aluminum. Which isn't an issue if you're working eroded beaches (where all such light stuff might be washed out in the riffle-board effect). But .... for places where aluminum abounds (junky parks), heaven-help the person who goes to turf like that, in search of micro-jewelry.
In fact, for *normal* lows (excluding "micro" for the moment), then I suggest that a large flock of machines can already get lows & mids, from junky parks, till your arms fall off. Simply lower the disc. knob, and .... I guarantee an apron full of mid and low conductors, from any junky park you step foot it. Thus it's hardly a hard-task, to find mids and lows from most places.
The only place I could see that machine, that favors mids & lows, would be on eroded beaches where you want those targets to have more "umph". JMHO