Well, this looks more like a workaround for a bug to me. It's definitely not recommended to still use intel X driver on Kabylake. The issue is, that we never really supported Optimus systems. Bumblebee may have worked on some systems, if you were lucky. My current guess is that Tuxedo preloads Leap 15 with Intel graphics disabled, proprietary NVIDIA driver preinstalled and possibly with a different desktop than KDE, but I simply don't know ...