Rocket, rather than use notch or discrimination, use the tones and tone breaks to your advantage, as they will not affect the depth performance of the Deus. Notch does in fact affect depth, it isn't a simple block on the audio, it is a discriminating filter for targets within a set range (XP confirmed).
This is just something I quickly knocked up, so just use it as a guide at this stage.
Using the tone breaks, you can narrow down a small section for the goldie range (with some overlap for on edge or deeper coins), and allocate a high tone frequency that suits your ears, and then allocate low tones for all the other tone break sections (using four or five tones). So essentially all you get are grunts for everything other than what falls within your set goldie range, and with no effect on performance.
Just go into Disc/Expert/4 or 5 tones/expert, then you can scroll down and change the tone frequency for each tone break, and after those it will prompt you to setup the width of each tone break section to suit whatever you are targetting.
So you could set your goldie range from say 81 to 91 to cater for on edge coins, though if you have the goldie section too small (say 85-87), you tend to get the low tones bleeding through with on edge coins, so you need to give it a bit of leeway either side for a clean high tone signal (have a play around and you will see what I mean). You can try and run lower than 91 for the top end of the goldie range, though I found that on edge goldies can strangely read high than if sitting flat, sometimes as high as 89 giving off a grunt or partial high tone. The same goes for notch with regards to setting a too smaller window.
No doubt those numbers will be subject to change knowing that they can vary a fair bit when in the ground, just need to have a play around to see what suits best.
Also setting the silencer high will help break up the high tones from rusty bottlecaps that fall around the goldie range, goldies will still come through nice and clear. As for aluminum bottle caps, you will still dig a few of those with them typically falling in the 80's range, though they do come across as more "forced" sounding targets than more mellow sounding coins.
If anyone else has a good setup for $1/$2 cherry picking, we will be glad to hear what works for you.