I read that too, and wonder about the usefulnes of this feature.

If your mouse has a sample rate of, say, 100Hz, what benefit does it bring to increase that to 1000Hz? You would still get 10 samples with the same data, then the next 10, and so on...

Or am I missing something here?

It just doesn't work the way you describe.

Many mice are capable of higher reporting rates than their defaults, they just need to be asked nicely.

But then the mouse "natively supports" 1000 Hz? OP said it helps with devices that don't "natively support it". The GitHub page calls it "polling rate overclocking" (whatever that means), which doesn't sound like it would "unlock" anything (or "ask nicely" as you put it) in the mouse but rather just increase the sampling frequency?

For reference, most mice sensors have sampling frequency in excess of 5000fps on the low end, but the data is consolidated and reported at a 125hz usb polling rate.