You are correct regarding the higher silver content 3p being able to be picked up by the G2, it just surprised me, as all had on hand for previously checking the discrimimation levels were post 45 ones, which were all discriminated out or part low tone at that setting. That was actually my first 92.5% silver 3p, followed by the 1943 and 1927 ones over the next week or so.
I had done some air tests on the 3p previously to see where it would cut out, and as you mention, you get rid of pull tabs, and you also miss out on most 3p, 20c and borderline on 50c, so essentially I was half expecting not to pick up on any threepence.p.
I have found though with the G2, that like many detectors, the accuracy of the discrimination falls away considerably at depth, so I am not discounting losing some of these smaller targets running such high discrimination. For example, the other night I checked a solid repeatable low tone, and was surprised to find it was actually a $1 coin, albeit a deeper one than usual. So you can see that some coins can actually move through the discrimination range, depending on depth and size of the coin.
It also shows how discrimination is not very accurate when items fall out of the effective range of the detector, and how air tests to see where items discriminate out don't really represent how the detector reacts to targets in the ground.
The Explorer is a different matter, it still seems to pick up well on high conductors at depth, but the VDI's may jump around by a digit or two. I usually use the explorer with an open screen with next to no discrimination.