I skimmed through the video posted and it's doing what I assumed it would be doing: forcing the driver to ignore what the USB device is stating as it's required polling rate. Unsurprisingly, the video doesn't show anything about confirming the results using a USB analyzer.
Here is a lesson about USB devices -- all communcation with the host (in this case the console or PC) is done through hardware and is disconnected from the act of producing new input. Think of it like a mailbox and you check your mailbox every day. Sometimes there will be mail in there and sometimes not. If you check your mailbox more often, that isn't going to change how often you get mail.
The the exact same thing as what I said above about the DS4. You can ask it for input as much as you want, but, it'll only reply with input every 8ms. If you use this thing to force the PC to ask at 1000Hz (1ms), it'll still only report input every 8ms (all other times the hardware will "NAK" -- which means it doesn't have anything to send). So, in the end, you still will be receiving input as fast as the device decides to send it. And you don't know what devices actually do unless you put it under a USB protocol analzyer and look.
