I just now had a situation where I needed to export a source template, but I exported the wrong source template to the correct Windows filename. So I did it again using the same Windows file name and exporting the correct template this time. It wouldn't export because the file name already existed. There was not an opportunity to approve the overwrite. It just wouldn't work.
The only solutions are to delete the existing template file from Windows or to export with a different Windows file name. Neither solution seems very friendly. Indeed, the first time I did this I didn't notice the message that the source template hadn't exported correctly and I sent the wrong template to a user who wanted a copy of one of my source templates. It was a puzzling problem to resolve after first failing to notice that the correct source template hadn't overwritten the incorrect source template.
Hopefully this behavior might be improved in RM8, preferably RM8.1 if fixing this would delay the release of RM8.0.