Interesting video there, Calabash. That's exactly what I have been planning to do in my own test garden, as soon as I get a block of time that I can set aside to do it. So, seeing you do it on the video here gives me a bit of a preview. Very good job.
I agree with whoever said it in your video, that it's a good idea to do a bit of testing at first, to see what "style" you like, in terms of those audio themes and profiles...alot of modulation...a little modulation...whatever you prefer, and then STICK WITH IT! In my opinion, the way to develop expertise as a detectorist is to really learn -- by careful attention to the audio nuances... listen, dig, note what the target is, and then do it again...and again, and again -- until your brain is able to associate certain subtleties and nuances, to specific targets at various depths, and in various positions relative to other targets. You are trying to "lock" those nuances in your brain, and what they mean, in terms of the target. HOWEVER -- if you then switch to a different audio theme/profile, the NUANCES you hear CHANGE. The targets SOUND DIFFERENT. And so, from my view, as you noted Calabash, you are making it harder on yourself if you keep changing your audio theme/profile. The GOAL from my view is to learn to associate certain SPECIFIC sounds and nuances of those sounds, with certain targets/target configurations. But if you are constantly changing your audio profile, you are then forcing those targets/target configurations to SOUND DIFFERENT. And to me, I can't see how that's helpful, when you are trying to learn a new machine.