I would setup multiple Parts that when used in different combinations achieve all of the desired layering.   Then use scenes to combine which Parts are layered and use keyboard control as the means to select layered Parts.

In some instances I would wish we could set note range with scenes and note shifts (true note shifts that do not pitch stretch) but these are not available.  Therefore I typically "burn" Parts to accomplish complex layering and splits that move.

I'll give that a shot - thanks. 

It's difficult to convey everything in a message (I didn't catch everything you were throwing about your goals) -- so maybe this example won't apply.  However, hopefully it will have something you can take to apply to what you're trying to do.

Say I want a split of strings to be on the low side of the keyboard (C0 - C1 range) for the intro because I have a string intro that goes straight into a synth lead on the right side of the keyboard (C#1 - top note on keyboard).  And then after this lead, which is part of the intro, I have bass parts I want split from strings and want to keep the bass in the left hand because my left hand is a better "bassist" than my right.

We can't just shift the strings to a different range by a button press.  That facility is not given to us.  So what I would do is this:

Part 1: Strings (C0-C1 range)

Part 2: Synth Lead (C#1-G8 range)

Part 3: Bass (C0-C1 range)

Part 4: Strings (C2-C3 range) - note shifted

Now, Part 4 is basically a copy of Part 1.  The only difference is because the "piano" keys being pressed are higher, we need to adjust down the pitch by 2 octaves so we get the same exact notes as Part 1.  So Part 4 would have note shift = -24 (24 semi-tones or 2 octaves).  A "note shift" in AWM2 does not stretch the pitch, but says if you're playing a C2, it's actually going to trigger the C0 sample.

And since my intro starts with Part 1 strings and Part 2 Synth lead, I would make Scene #1 have keyboard control ON for Parts 1 and 2 and then keyboard control OFF for Parts 3 and 4.  And I would make sure that the Performance is saved such that Scene 1 is active when recalling this Performance.

Then I would set Scene 2 to have keyboard control OFF for Parts 1 and 2 and then keyboard control ON for Parts 3 and 4.

Here I would say that I "burned" Part 4 in order to accomplish this shifting of the keyboard range where the sound is triggered from.  It's not the only way to do this, but how I most often use resources.

There was a time when we couldn't save keyboard control into scenes.  And during that time I would have use Part mute instead.  There's nothing wrong with using mute if there is no overlap between scenes.  Meaning that what is getting muted is not going to be sounding as you change scenes.  If I did all of this with mutes then say the end of my intro I hold a synth high note and the bass (scene 2) comes in while that note is held.  If I used mute then when I switched to scene 2, the synth lead would instantly be muted and cut off.  Keyboard control wouldn't cut off during a scene change until you lifted off the held key.

Other food for thought ...

If you're trying to add an octave to something you could also experiment with effects.  There's an effect under the "MISC" category called "Pitch Change" and you could use this to add an octave, 5th, etc.  It allows for 2 different pitches each "instance" of the effect used.  You could either replace one or both insertion effects or use a variation (one of the system) effect.  Either way you can set how much of the original pitch and the effect'ed pitch would sound.  The effect may or may not be the quality of sound you're looking for.   Then you could use "output level" (a parameter for each of the 2 pitches in the effect) or other means to turn on/off this effect - or parts of the effect.  Using assignable knobs to offset the level and superknob to move the assignable knobs which can be used in scenes to set the superknob position.  Or move away from scenes and have the [ASSIGN 1&2] buttons turn on and off different pitch change effect notes using these buttons instead of assignable knobs to offset the same destination parameters (effects).