Import / Export add on

a question. I received the notification about the theme update. Nice i like updates, but as the English is not my native language i am not sur if i understand about the import export.
So.. i have made my modifications.. but with the new update maybe will have trouble.
Can i use the import/export add on instead of using a child theme(actually i don't know yet to create child themes). If i export the default settings these are the defaults of the theme before or after my modifications?
thanks in advance and keep on your great work...