I'm confused, but of what possible use could this knowledge be to anyone?
These are all proprietary system, and written into ROM chips (if sound data) or in imbedded copyrighted OS's.
You could find yourself in quite a lot of trouble were you to actually publish this kind of information (which wouldn't be of any use to anyone short of a competitor manufacturer, anyway)..
Perhaps just the OPERATIONAL aspects are what you should concentrate on. But be prepared to do a lot of the work yourself... seek times on HD's in arrangers are NOT part of the published spec. Test them for yourself, and be prepared to be exhaustive if you want an accurate answer...
But, in all truthfulness, as technical as I like to get sometimes, I'm not the slightest bit interested in the HOW... But I am FAR more interested in the WHAT...
How long does it take to load a style from HD. Does the disk being full make a difference? Does the disk being fragmented make a difference? Do OS upgrades make a difference...
Practical stuff like this you can test for yourself. But what part of the memory address gets used for user styles, what gets used by ROM sounds...? Who cares?
As long as it works...