FreeFileSync Forum

I think Update will do what you want.
Go to Actions on the tool bar, select Synchronization Options, then select Update.
The tool tip for Update says: "Copy new and updated files to the right folder"

Oops, Looks like this has already been requested in "Enable/Disable folder pairs" thread.
Wasn't looking for Enable/Disabe when I was searching.

I would like to see a check box by each folder pair, and a select all check box in FreeFileSync
That would allow you to run only against folder pairs you ...