That is not a USB 2.0 header is its with the ROG EXT header. Chances are you have only one header and need to use a hub if you have multiple devices.
My Z270E mobo manual shows the ROG EXT header alongside a second header USB1314 (confirming 2.0 USB) and refers to both of these as 'ROG EXT connectors'. I'm assuming some or all ROG devices plug into both of these headers. Though both headers are referred as ROG connectors, the manual fails to mention whether the USB1314 can be used as a regular USB header too, in the absence of ROG devices.
Would it be safe to try the HUE+ on it to see if it works? I double checked viewing the online manual too (assuming its an updated version)
and it too confirms USB1314 as a 2.0 USB connection.
There is only 1 USB 2.0 header. I use a powered internal usb 2.0 hub**