I have installed the image on my OnePlus 5.

This is my test result.

Actors: Manual brightness //Works
Actors: Notification LED //doesn't work
Actors: Torchlight //works
Actors: Vibration //works
Bluetooth: Driver loaded at startup //doesn't work
Bluetooth: Enable/disable and flightmode works //doesn't work
Bluetooth: Persistent MAC address between reboots //unknown
Bluetooth: Pairing with headset works, volume control ok //unknown
Camera: Flashlight //works
Camera: Photo //works
Camera: Video //works but Media Player app can only play the first frame (video file works on PC)
Camera: Switch between back and front camera //works
Cellular: Carrier info, signal strength //works, not stable
Cellular: Data connection //works
Cellular: Incoming, outgoing calls //doesn't work and sometimes crashes (VoLTE-only carrier)
Cellular: MMS in, out
Cellular: PIN unlock
Cellular: SMS in, out //SMS in works. SMS out doesn't work
Cellular: Change audio routings
Cellular: Voice in calls
Cellular: Switch connection speed between 2G/3G/4G works for all SIMs
Cellular: Enable/disable mobile data and flightmode works //works
Cellular: Switch preferred SIM for calling and SMS - only for devices that support it
Endurance: Battery lifetime > 24h from 100%
Endurance: No reboot needed for 1 week
GPU: Boot into UI //works
GPU: Hardware video decoding
Misc: Anbox patches applied to kernel
Misc: AppArmor patches applied to kernel
Misc: Battery percentage //works
Misc: Offline charging (Power down, connect USB cable, device should not boot to UT) //doesn't work, boot to OnePlus logo and hang?
Misc: Online charging (Green charging symbol, percentage increase in stats etc) //works but no charging symbol
Misc: Recovery image builds and works
Misc: Reset to factory defaults
Misc: Date and time are correct after reboot (go to flight mode before)
Misc: SD card detection and access - only for devices that support it
Misc: Shutdown / Reboot //works
Misc: Wireless charging - only for devices that support it
(Network: NFC - disabled atm due to no middleware)
WiFi: Driver loaded at startup //sometimes WiFi status is not shown right. try rebooting
WiFi: Enable/disable and flightmode works //works
WiFi: Persistent MAC address between reboots //works
WiFi: Hotspot can be configured, switched on and off, can serve data to clients //works but interferes with WiFi. Hotspot status is not shown right.
Sensors: Automatic brightness //works
Sensors: Fingerprint reader, register and use fingerprints (Halium 9.0 only) //doesn't work
Sensors: GPS //doesn't work
Sensors: Proximity //works
Sensors: Rotation //works
Sensors: Touchscreen //works
Sound: Earphones detected, volume control //works
Sound: Loudspeaker //works
Sound: Microphone //works
Sound: Loudspeaker volume control //works
USB: MTP access //works
(USB: ADB access - disabled atm due to no middleware)
USB: External monitor - only for devices that support it //doesn't work

sshd works
apt doesn't work
Libertine doesn't work
USB keyboard and mouse works
back button, home button and menu button doesn't work

I have found how to workaround the WiFi symbol and AP list problem.
Connect from ssh and restart the desktop with the following command.

sudo service lightdm restart

This doesn't work when executing from the internal terminal. The phone just goes black.

@michi2302
You need the phone to be in TWRP to run halium-install-standalone.sh.
The filesystem you see from adb in TWRP and in Android/Ubuntu Touch is different.
I think recovery.img contains the original recovery, which I can't find how to use adb to connect to.

@michi2302
I don't know. But
fastboot boot twrp-xy.img
will not overwrite your boot or recovery partition on the phone. The phone will boot directly from the image file.

@michi2302
You can fastboot into TWRP and use adb shell to connect to your phone and examine the image files.
They are in /data/.
android-rootfs.img (size 487022592)
rootfs.img (size 3221225472)
Sizes from my working OnePlus 5.

You can also check if you have flashed halium-boot.img and vendor.img.
fastboot flash boot halium-boot.img
fastboot flash vendor vendor.img

I have installed the image on my OnePlus 5.

This is my test result.

Actors: Manual brightness //Works
Actors: Notification LED //doesn't work
Actors: Torchlight //works
Actors: Vibration //works
Bluetooth: Driver loaded at startup //doesn't work
Bluetooth: Enable/disable and flightmode works //doesn't work
Bluetooth: Persistent MAC address between reboots //unknown
Bluetooth: Pairing with headset works, volume control ok //unknown
Camera: Flashlight //works
Camera: Photo //works
Camera: Video //works but Media Player app can only play the first frame (video file works on PC)
Camera: Switch between back and front camera //works
Cellular: Carrier info, signal strength //works, not stable
Cellular: Data connection //works
Cellular: Incoming, outgoing calls //doesn't work and sometimes crashes (VoLTE-only carrier)
Cellular: MMS in, out
Cellular: PIN unlock
Cellular: SMS in, out //SMS in works. SMS out doesn't work
Cellular: Change audio routings
Cellular: Voice in calls
Cellular: Switch connection speed between 2G/3G/4G works for all SIMs
Cellular: Enable/disable mobile data and flightmode works //works
Cellular: Switch preferred SIM for calling and SMS - only for devices that support it
Endurance: Battery lifetime > 24h from 100%
Endurance: No reboot needed for 1 week
GPU: Boot into UI //works
GPU: Hardware video decoding
Misc: Anbox patches applied to kernel
Misc: AppArmor patches applied to kernel
Misc: Battery percentage //works
Misc: Offline charging (Power down, connect USB cable, device should not boot to UT) //doesn't work, boot to OnePlus logo and hang?
Misc: Online charging (Green charging symbol, percentage increase in stats etc) //works but no charging symbol
Misc: Recovery image builds and works
Misc: Reset to factory defaults
Misc: Date and time are correct after reboot (go to flight mode before)
Misc: SD card detection and access - only for devices that support it
Misc: Shutdown / Reboot //works
Misc: Wireless charging - only for devices that support it
(Network: NFC - disabled atm due to no middleware)
WiFi: Driver loaded at startup //sometimes WiFi status is not shown right. try rebooting
WiFi: Enable/disable and flightmode works //works
WiFi: Persistent MAC address between reboots //works
WiFi: Hotspot can be configured, switched on and off, can serve data to clients //works but interferes with WiFi. Hotspot status is not shown right.
Sensors: Automatic brightness //works
Sensors: Fingerprint reader, register and use fingerprints (Halium 9.0 only) //doesn't work
Sensors: GPS //doesn't work
Sensors: Proximity //works
Sensors: Rotation //works
Sensors: Touchscreen //works
Sound: Earphones detected, volume control //works
Sound: Loudspeaker //works
Sound: Microphone //works
Sound: Loudspeaker volume control //works
USB: MTP access //works
(USB: ADB access - disabled atm due to no middleware)
USB: External monitor - only for devices that support it //doesn't work

sshd works
apt doesn't work
Libertine doesn't work
USB keyboard and mouse works
back button, home button and menu button doesn't work