Login screen should be mirrored to all displays by default

I have laptop connected to external display. I do not use the laptop display. I find it strange that login screen is only shown on laptop display. Ideally the login screen should be mirrored to all displays. What happens after login can remain as is.

Right now, even though I have changed my used settings to use external display only, the login screen is not visible at all on external display. IMHO this is less than ideal way, and I would like to suggest that the login screen is shown on all displays.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: xorg 1:7.7+19ubuntu8
ProcVersionSignature: Ubuntu 4.18.0-15.16-generic 4.18.20
Uname: Linux 4.18.0-15-generic x86_64
ApportVersion: 2.20.10-0ubuntu13.2
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Wed Mar 6 10:15:29 2019
DistUpgraded: Fresh install
DistroCodename: cosmic
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Dell UHD Graphics 620 [1028:07e6]
InstallationDate: Installed on 2019-02-20 (13 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
MachineType: Dell Inc. XPS 13 9370
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-15-generic root=UUID=aafb7db0-5383-4a5a-9181-90baaaf77212 ro quiet splash vt.handoff=1
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/04/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.6.3
dmi.board.name: 0F6P3V
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.6.3:bd11/04/2018:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn0F6P3V:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 13 9370
dmi.product.sku: 07E6
dmi.sys.vendor: Dell Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.95-1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.2-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.1-3ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-3