Warning: I may not be qualified to answer this question. However, I have an IE320 socket with no fuse, between my smart strip and wall power. As I see it, it's no different electrically than plugging my smart strip directly into the walls, it's basically a nice extension cord. And, I would have no problem plugging a pc, monitor into the smart strip then straight to the wall without an added fuse.
That being said, a lot of premade ie320 ports with switches do have fuse holders, so I'm sure there are some applications where fuses are desirable.