I don't have a keyboard that uses YEM as the expansion memory manager so I can't confirm the following, but I like to stay up to date with YEM and have it installed on my computer along with a S970 installed as a 'target' so that I can play with the program!
I notice that once styles (or Registration banks or Multi Pads) are in YEM (either imported as part of a PPF, or individually as pack content), when you select them to include in a PPI for an S970, only the 'User Drive size' memory requirement increases, not the 'Audio Wave size'.
I am aware that expansion voices require a small amount of space on the keyboard's USER drive as well as space in the dedicated expansion memory, but I had assumed that styles, registration banks and MPs are only ever loaded to the USER drive, and this would appear to be the case.
Can someone confirm this, because if it is the case then I can't see any advantage in using YEM to load only styles to the keyboard. Do they perhaps they go into a 'pack' folder on the USER drive which I suppose might make them easier to find?
If a pack is deleted from the keyboard, or a different pack installed, does this delete any styles/regs/MPs loaded as part of previous packs?
If it does, then loading styles to the keyboard by simply copying and pasting them from USB to a folder created by you on the USER drive would use just the same amount of memory as installing via YEM, and would seem to be more 'permanent'!