HP Zbook Studio G4

Sound Card
Be sure to enable (snd-hda-intel) and enable the codecs.

Thunderbolt 3
Thunderbolt 3 is a hot pluggable PCIe port, with USB 3.1 support.

Should be enough.

USB
Easy, just enable xHCI.

No need to enable EHCI or OHCI. xHCI is backwards compatible already.

Wifi
Intel Corporation Wireless 8265 / 8275 does not work out of the box.

Look for the iwlwifi firmware in the lib64 directory.

The following kernel config is copied from here.

No need to enable DVM:

Hardware Wifi Button
To enable the Hardware Wifi button (no LED feedback as of yet):

Nvidia Optimus
Configure according to NVIDIA/Optimus & the NVidia/nvidia-drivers articles.

This is the necessary xorg configuration:

Be sure to switch the OpenGL drivers before starting X:

Intel
See the intel page for up-to-date kernel parameter instructions.

Configure xorg to use intel driver.

Rebuild changed packages.

Emerge the dated Intel HD Graphics driver.

Configure xorg file.

NVidia
Disable all Framebuffer devices except the EFI framebuffer. Others may interfere with the boot process, in which you'll may experience a boot freeze.

This should be a sufficient xorg configuration to  correctly.

Bluetooth
Follow the Bluetooth article on configuring and using Bluetooth.

HP 3D Driveguard
HP 3D Driveguard is a feature of HP laptops that turn off the hard drive when the laptop is falling. To enable HP 3D Driveguard, follow the instructions of the HPfall article.

External DisplayPort monitor does not work on PCIe(Thunderbolt 3) port
When using an adapter to connect an DisplayPort monitor to the PCIe port and the monitor does not get recognized, the solution is: Now it should work!
 * 1) Make sure the adapter is not plugged into the PCIe port;
 * 2) Disconnect the DisplayPort cable from the adapter;
 * 3) Plug the adapter into the PCIe port;
 * 4) Connect the DisplayPort cable.