The Sovereigns have to see the ground matrix in order to compare it to a target, without it it seems to lose the depth.
Now 10 inches on a dime in a air test sounds a little far as most will only get around 6 or 7 inches I have did air test on, but in the ground I have got them up to 11-12.
Now i will say my experience with the Elite it seem to me the coins sounded deeper than the actually were, but it still seem to get them with no problem, just sounded deeper and had to listen close to the tones more. On sensitivity it is odd you are at max as you know that is only a click out of auto and your Elite should be unstable at this setting if there is any iron at all around. I can run only at max at clean sites and wonder who did the silent search mod on your Elite. If you bought it used I wonder if someone tinkered with some of the other thing in the box when they had it open. I never like the silent search and felt I missed the real deep coins, but in cleaner area where targets were far a few between the silent search worked good so you didn't have to listen to the low growl of iron.
Remember to get the deep one you have to go slow and listen, but if 2 -4 inches is all you can get i would try lowering the sensitivity and going slower and listen more as with the Silent search it it could be nulling and you don't know it and can be going over many coins deeper as you are going too fast. With it nulling and you can hear it you will go slower and hear the deeper ones, but in silent search you don't know it is nulling so you don't slow down.
Give it a try and see what happens.
Rick