The air test does not indicate this. I'm sure discriminate uses some power to determine iron but with a full charge it's cracking on the beach. I have tried it and may do some more this winter now that I've cleaned house not much left.
Air tests are not a real good indicator of depth ability on a Minelab. I find lots of signals in PP that are completely silent in Disc because the target is deeper than the discriminator circuit can detect it.
Nice upgrade you have there. I was torn between the straight shaft and the Anderson over/under. Went with the Anderson but have yet to install it as it is a Xmas present.
You're going love the Excal attached to the plugger CF shaft. The balance is so good you'll be concentrating on the sounds as the coil floats over your targets. Best of luck!