No there is no way to know what the last loaded set was..
I would suggest as well that you could FTP to the USB drive using a client like Filezilla works great. Then you can rename the Standard SET0 through SET9 folder to other names.. you can also Add folders that will show up available.. So you could make a new folder with a Date or other name to save a copy of that file and have as many setup files on the usb as you would like.
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Les O'Reilly
Director - Switcher Product Management
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