As a new owner of the Optimus Pro XI the touchpad driver package also confused me.
When downloaded it has an attached pdf that suggests the drivers are Pixart, although it installs as "Hid compliant mouse"
It works as I would expect a touchpad to work so no big issue.
I looked on the XMG site for the core17 and it has an updated Bios (which I will not be installing) that includes a Pixart update.
It could do with some sort of explanation from PCS as to what is needed.