While it already worked in the Bluetooth mode, it didn't without a load of tinkering with the dedicated low-latency dongle. Nice to see Valve move quickly to support third-party pads like this. Must admit my own temptation to pick one up has increased. Seems like a nice controller, especially nice with the back paddles too.
Other additions in the update include rumble support to the built-in hid-steam controller driver and they fixed a USB crash when using certain controllers such as the Hori Fighting Stick α.