Hi NASAMike,
the 'Voices" in a Pack subfolder inside the "Expansion" folder on the User drive are only so called Voice Set files (.vce). These files are very small (1 - 5 KB). You can copy/save such a file to a location outside the Expansion folder, but you will get ... exactly the same file. You can use a .vce file to call up the corresponding Voice. But this only works when this Voice is correctly installed on the instrument.
Note:The .vce file is NOT the complete Voice (since the Wave data of an Expansion Voice is stored in the separate "Expansion Wave NAND Flash" memory).
You cannot copy or export an Expansion Voice to a USB stick and use it while the original installed Voice or the whole Pack was deleted from the instrument.
The only option to save space in the Expansion Wave memory is to deselect unneeded Voices in the YEM and then install this "reduced" content on the instrument. But be careful: If a Pack also contains Styles, some of them could need such deselected Voices.
Best regards,
Chris