Now, I’ve personally tested it by switching to an Android ROM, wiping the 4 Partitions and then restoring this backup, so yes I can confirm that it works!
What you need:-
TWRP 2.8.6.0
The TWRP Backup
WinRAR (32 bit or 64 bit)
Instructions:-
1. Download the Backup and TWRP
2. Flash TWRP, I’d recommend using the official TWRP 2.8.6.0 to avoid any issues.
3. After downloading the backup(5 Files), copy them all in the same folder and extract the one without any .z extension. I splitted them to avoid any issues with files bigger than 4GB, because the backup is 4.01GB in size.
4. After extracting you’ll find a single TWRP folder, connect you device and copy it to the main directory of your device’s storage, Click "Yes" if it asks for replacing any files.
5. Boot into TWRP and Backup your ROM(Optional)
6. Go back to the main TWRP Home screen->Press Wipe->Advanced Wipe->Mark Dalvik Cache,System,Data and Cache (Make sure you don’t tick Internal Storage or USB-OTG).
7. While in TWRP, go to the main home screen and press Restore, there select "Ubuntu Touch" and leave all the 4 Boxes checked. Then, Swipe the button on the bottom and wait. The Numbers won’t get updated but don’t worry, it is getting restored and can take around 3-5 minutes.
7. Restore the backup. It will stay on the 1+ logo for a while so have some patience.
Disclaimer: I am not responsible for bricked devices, dead SD cards, thermonuclear war, or you getting fired because the alarm app failed. YOU are choosing to make these modifications, so don’t point the finger at me for messing up your device.