libinput: How to properly set up trackpads to inverse scroll in 16.04 and onward for Logitech wireless keyboards + trackpads?

Question

I found a real nice answer here that would be great if it worked: https://askubuntu.com/a/820098/134500

I'd like to use libinput to get scrolling to work properly as well as other trackpad and pointing functionality. When I attempt to enable it, unfortunately the keyboard + trackpad (Logitech K400+) entirely stops working.

Under /etc/X11/xorg.conf.d I have:

20-touchpad.conf:

Section "InputClass"
    Identifier "libinput touchpad catchall"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"

        Option "NaturalScrolling" "on"
        Option "MiddleEmulation" "on"
        Option "Tapping" "off"
        Option "DisableWhileTyping" "on"
EndSection

30-pointer.conf

Section "InputClass"
        Identifier "libinput pointer catchall"
        MatchIsPointer "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"

        Option "NaturalScrolling" "on"
EndSection

I thought that libinput was already active on 16.04, however, as noted, input for the keyboard stops altogether. I'm not seeing an issue in the logs. Any thoughts on how to ensure that libinput is working and on how to get it to work with this Logitech K400+?

Perhaps libinput is Wayland only and since this is running xorg this is the dilema in this instance? If so, what's the right approach here?