Bryce,
Those are some interesting settings. I have an old fairgrounds about 50 miles from me that has a patch of crappy soil with gravel mixed in it. Last time it was hunted, a standing lib qtr and a barber qtr came out of there, but because of all the trash and constant noise from the machine, it was pretty much an accident that I heard the high pitch amongst all the trash. It seems to me that adjusting to semi auto (I assume you're at sens 32 setting...) and a low amount of iron mask would 'smooth' out things so that the coin sounds are easier to pick up...is that about right? Also, in conductive sounds, how do you get around the nails? For me, nails usually show up in the upper left, while rusty bottle caps seem to settle in the lower right. I think blacking out a small section there would eliminate the sounds but I'm also afraid of creating too much nulling and missing close good targets. Of course, if the SE 'averages' the sound, or still allows the high pitch to come through, maybe that won't be a problem. Way in the past, with the old analog machines (VLF/TR) you could still get a good 'clip' on a coin if it was next to trash that was discriminated out.
As I said before, I've got both the SEF 10X12 and a 6" Excelerator coil coming and it seems to me that a combination of the two should do a pretty good job in that trash patch, and maybe get some dimes overlooked by others. You've stated more than once how good the depth is on that little 6 inch and it may be the ticket for working the area a small section at a time.
Knipper