This is technical thing. Without files stored locally, you would have to upload it again and again with every change. And you would have to enter their locations again and againd, because security rules in modern browsers prevent server to "pre-fill" input field with previous file name.
But there is no way for anyone to get this stored files without knowing their exact ID (40 characters long hexstring generated as SHA-1 hash of TYP content). You can be absolutely sure that nobody can browse or download any TYP file stored on this server.
K TYP souborům uloženým na serveru se bez znalosti jejich přesného obsahu nikdo nedostane. Jejich identifikátor je odvozen od SHA-1 hashe generovaného z jejich obsahu. Můžete si být zcela jisti že si nikdo nemůže jen tak prohlížet TYPy uložené zde na serveru.