2020/02/10 Re-installed from 19.10 to 18.04.
Turn on the power and F2 on the POST screen (Is it correct to say EFI instead of BIOS now?)
Make it AHCI Disable Secure Boot Make Fast Boot Thorough
Turn on the power and F12 on the POST screen
Install in safe graphics mode
When I open Language Support, an incomplete language environment appears, so install it. After rebooting, you can add Mozc from Input Sources in Region & Language in Settings. After adding Mozc, restart it again and Mozc is enabled.
gsettings set org.gnome.desktop.input-sources xkb-options "['ctrl:nocaps']"
It sleeps but does not wake up. See [here] on the Arch Wiki (https://wiki.archlinux.org/index.php/Dell_XPS_15_7590#Suspend). Don't forget to regenerate the configuration file by executing the following command after setting.
$ grub-mkconfig -o /boot/grub/grub.cfg
You can do it with libinput-gestures.
Install GNOME Tweaks from Ubuntu Software. You can set Mouse Click Emulation in Keyboard & Mouse to Finger.
I installed Sophos Anti-Virus for Linux.
I will write it later. Reference: https://blog.katio.net/page/linux-bluetooth
XPS 15 (7590) is exclusive control of NVIDIA GeForce GTX 1650 and Intel UHD Graphics 630. The GeForce driver is correct when Ubuntu is installed. (You may need to check for third-party software at the time of installation.)
On the driver settings screen, --Always use GeForce --Always do not use GeForce (always use Intel UHD Graphics 630) Can be selected. Automatic switching is not possible and GeForce always ON or always OFF 2 choices.
Only 100% / 200% / 300% / 400% can be selected. It seems that you can choose 150% with xrandr, but I have not tried it, and if GeForce is enabled, I run into the problem of ↓.
In my environment, I connect a 4K external display in addition to the 4K display of the main unit. Arch Wiki [here](https://wiki.archlinux.jp/index.php/HiDPI#.E5.A4.96.E9.83.A8.E3.83.87.E3.82.A3.E3.82. B9.E3.83.97.E3.83.AC.E3.82.A4),
Note: The above --scale 2x2 does not work on some Nvidia cards. No solution has been found so far . This can be temporarily avoided by setting ForceFullCompositionPipeline = On in CurrentMetaMode using nvidia-settings. See  for details.
Scaling does not work well when using GeForce as written. If it is 100% or 200%, there is no problem, but if it is not, the desktop will be displayed outside the actual screen. I haven't tried a temporary workaround yet. (As of December 25, 2019)
Use lm-sensors, write later.
Use ffmpegthumbnailer, write later.