Theme File Duplicator to replace use of Child Themes?

I am using the Twenty eleven theme and wanted to make a number of visual changes without modifying the original theme coding. Searching Forums indicates creating Child Themes are the way to go about this but my host is doing this as a favour and I don’t want him to have to put in additional work. Also takes a long time to get a response. I thought the ‘Theme File Duplicator’ might be an alternative way to go – is this possible or do I still have to set up the initial Child Theme through an FTP before this plugin becomes useful for me?

https://www.ads-software.com/extend/plugins/theme-file-duplicator/