Device info https://wiki.lineageos.org/devices/paella
Rom https://www.androidfilehost.com/?w=files&flid=299505
Please Note: This is an Untested build. Please try at your own risk.
I made an update for this device, enjoy 
:
e-0.9-n-20200628-UNOFFICIAL-paella.zip
TWRP : https://twrp.me/bq/bqaquarisx5.html
Don’t forget to backup and share your experience, thanks 
Hello Anonyme,
tried out e-0.9-n-20200628-UNOFFICIAL-paella.zip on my Aquaris X5.
Was not so easy to get it going, coming from LineageOS 7.1.2.
Machine is Debian Buster modified Kanotix from here:
http://kanotix.com/, with ADB & Fastboot installed. First step flash twrp-3.4.0-0-piccolometal.img (as su: adb reboot bootloader/ fastboot flash recovery twrp-3.4.0-0-piccolometal.img/ fastboot reboot).
After restart, press on/off button, restart, recovery (this assumes you have enabled developer options & expanded restart menu).
Copy e-0.9-n-20200628-UNOFFICIAL-paella.zip to a micro SD card & put it in the phone.
In TWRP, I had to do a full wipe, so go to extended wipe menu, clear cache, data, system, internal memory, then format data. THIS DELETED EVERYTHING ON YOUR PHONE.
Then, and this is the step I missed first, go to TWRP start menu, say restart recovery, and now you can flash the paella.zip from above. It is not enough to use the back button to go to the TWRP start page; your install will fail with “error 7”. You have to use the restart menu option.
User “manjar” in the German forum helped me with this
(BQ Aquaris X5 (paella)), so a big “Thank You!” to him.
My 4 years old Aquaris X-5 has won a new lease of life now, with security updates from June 2020. I’ll report any issues, battery life, etc. Seems to work fine, so many thanks to the developers!
One wish: I would love to have more control over which apps to install & which to delete & not just disable them. Is this possible?
PS: User manjar has also made a new build based on Oreo; I’ll try that next.
USE AT YOUR OWN RISK!