Roger, say you want to do a performance save, SD, save, technics, position, page 2, custom, switch yes. Then the entire custom is saved with any sequencer contents or panel memories used with any custom style. If someone alters the custom it can be restored same as before, just as any combination of sections on the page 2 save.

For imexport, read the sd tools section on page 45, export a midi and the folder is automatically created, fill it with midis in a card reader and then import them in the same menu.