I've got an annoying clutch fork rattle at idle and low speed. I'm not sure why; there doesn't seem to be any excess play in the fork, but it's allowed to move up-and-down a bit. The spring gizmo on the TO bearing end is in place, and the rubber gizmo at the pivot ball is intact. I've never noticed the noise much before, but as time goes on I've been eliminating noises and vibrations, so it's noticeable now. The motor doesn't shake much at idle, despite the sidedrafts, but it's enough to rattle the fork.
On non-hydraulic clutch setups there's a coil spring that keeps the fork tight up against the actuating rod. We can't do this easily on the hydraulic setup because it pushes the actuating rod back into the slave cylinder. I suppose a spring gizmo that attaches the fork to the slave actuating rod might work.
I'm also contemplating applying some sort of rubber, even silicone caulking goo, to the area around the actuating rod end.