I have a Dell XPS 13 (9360) with Fedora 26 installed. Very happy with it.
UEFI boot from flash drive works out of the box.
For install I needed to change the drive settings in the BIOS from the default of RAID (what ever that means on a laptop) to AHCI. No need to turn off secure boot.
If you want to use a DisplayLink USB display adaptor like the D3100 (commonly sold with this laptop), you might want to checkout https://github.com/displaylink-rpm. This will require either you to turn off secure boot or to sign the displaylink modules after they are installed. Signing is not that hard, but is a extra step that you have to look after.
Cheers,
Kal