If it only affects the temp files, then it wouldn't be a silly idea - even for Firefox.
As a supporter, I'm used to here people opening stuff in their browser/mail and hitting save, when they close the external program. They're just forgetting where the file actually is located on the disk, so usually the edited data is lost.
We can't educate non-IT people through a program, so why not help them a bit?
If it only affects the temp files, then it wouldn't be a silly idea - even for Firefox.
As a supporter, I'm used to here people opening stuff in their browser/mail and hitting save, when they close the external program. They're just forgetting where the file actually is located on the disk, so usually the edited data is lost.
We can't educate non-IT people through a program, so why not help them a bit?