Here's how I got Ubuntu 18.04 working on the Dell "New XPS" 9570 with the i9-8950HK. Note that I only used this to setup Linux-only machines. Good luck!
- Change SATA Operation from RAID to AHCI (this probably messed with Windows, but I don't use Windows on this machine)
- Disable secure boot (we'll be using an unsigned kernel. you can sign it etc yourself if you want; good luck)
- Disable microphone (optional)
- Disable webcam (optional)