That's a recent invention. Only the latest gaming mice can poll at that rate, and not particularly well on USB2. They're usually limited to 1000.

Neat tool, though. I'm also very sensitive towards latency.

most of 8k dongle is usb 2

Of course, that's necessary. Many USB ports "designated" for keyboard and mice are still only USB 1.1, and my post should have said unless on USB 2. You need USB 2 in both the mouse/adaptor and port to get full performance.