You can choose which button to wake up the PC.
In the MISC tab of JoyCon Explorer,
check off "By Keyboard", "By Remote controller", "By Any Button"
and check on "By Assigned button"
and assign the button you want to use for wake up PC.
(If you want to wake up PC after x seconds button holding, assign "Long Button" )
You can wake up PC from sleep with the button.
The other buttons can be used for LEDs control.
If the USB port is powered while PC sleep, you can control LEDs while PC sleep.