If a file is modified at a dropzone, it will be overwritten with the latest release (if that file is modified in the package). So, if I have an index.php file

If a file is modified at a dropzone, it will be overwritten with the latest release (if that file is modified in the package). So, if I have an index.php file that is never updated, then a dropzone modification of index.php will live forever because a new index.php will not be uploaded. Otherwise, if the index.php in the package is updated, it will be overwritten.