Your English is excellent, but this paragraph is where I lost comprehension. "Overlapping frequencies" don't prevent you creating "new sounds in a real additive way" from "elements/layers extremely easily" - just layer a square wave and a triangle wave on a Minimoog for proof. And I don't know what "well-aimed elements/layers from an external instrument source" is, let alone one "of mine".
I think you're saying that you can provide me with a sound which is, say harmonics 1, 3, 6, 12 and 15 - and a separate sound which is 2, 4, 8 and 10 - and another sound which is harmonics 5, 11, 13, 14, 16 - and when you layer them there is no duplication of harmonics. Am I right? And if I am - why is this such a big deal?
Cheers, Mike.