Dear Maintainer, This bug is still present on Debian Sid (version 4.14.2-1). I suspect this is because xfce4-settings doesn't have the libinput10 package as a direct dependency (or xserver-xorg-input-libinput, not sure which one is relevant here), and the xfce4-settings source code contains a bunch of #ifdefs that depend on the presence of libinput, so if the headers aren't included during compile time, libinput-specific options won't be enabled in the final binary. Of course, one could always manually compile it from source with xserver-xorg-libinput-dev installed, but, seeing as how the Synaptics driver is deprecated, and Xorg is required to run Xfce, I think it'd be a good idea to include it as a dependency.
Thanks for reading, Goran
