It seems the most reliable way to get the right-click to work with two fingers only is explained here and is the one referring to editing synaptics.conf. synclient doesn't seem to work. Having said that…seems like a had a note to do this: * synclient RightButtonAreaLeft=1180 * synclient RightButtonAreaTop=1180

update: did this, then edited /usr/share/X11/xorg.conf.d/40-libinput.conf 

Section "InputClass"
        Identifier "libinput touchpad catchall"
        MatchIsTouchpad "on
        MatchDevicePath "/dev/input/event*"
        Option "Tapping" "False"
        Option "AccelProfile" "adaptive"
        Option "AccelSpeed" "0.3"
        Option "ClickMethod" "clickfinger"
        Driver "libinput"
EndSection

* disable touchscreen:

xinput --disable $(xinput --list | grep -i 'touchscreen' | grep -o 'id=[0-9]*' | sed 's/id=//')