In Elements 3.1.3 (build 24707), Smart Publishing appears to republish unchanged files, both locally and over FTPS.
In a local test, two consecutive normal publishes with no edits between them:
-
Rewrote 60 of 61
.asppages with identical contents. -
Rewrote all 61 CSS files: 47 had different contents, while 14 were identical.
“Clear page status when publishing” is enabled. This happens using the normal Publish button.