Joe I added a GB control to my XP Pro, but I have not owned a CS Pro, however I have played with them before. I never did have to work on them because they never seemed to break down.
The two or 3 tone was a factory special order choice. Now of course you need to know that a Compass will go from 5 or 6 inches in air on a nickel to as much as 11" if you passs the coin in front of it real fast. In other words, (up to a certain point) Compasses will go deeper - the faster they are scanned.
As I said earlier, if you can't get around 10" or more in air scanning quickly, it needs to be sent to Keith for a tuneup.
And here is a test to try;
Place several pennies 3" apart in a row. Scan the detector quickly over them (inline) with them. You should be able to hear every one of them if you are swinging at a rate of 1-4 fps. No try that with a Tejon too. Both of them should handle that very well, then after that replace every other penny with a steel screw about 1" long. The Compass should cancel the screws in-between the sounding off of the pennies when scanning at a seriously fast rate, but the Tejon probably will not do it. If your Compass can't do it, it needs to have a tuneup.
Now even though the Tejon has a lot of trouble with it's high gain in high iron soils, it is probably the most superior of all detectors in finding the pennies even closer together in a straight line, as close as 2" apart. However, the Compass will outperform it when bad targets are placed in-between the good targets. In trash-filled soil though, yes, by all means, slow the scanning rate down. And no, not myself nor anybody else has enhanced the depth on my XP. They came out of the factory getting at least 10" in air on a nickel, and the GS Pro and R&C got another 3"-4" more than that.
Larry