I have done an install end to end on a Pixed3a having Android 12 using a VM (Virtual Box 6.1).
What you do is at your own risk
Executive summary here:
- You will have an unlocked bootloader at the end of the port. That cannot change, is not a drawback in my view - but read about before you panic and compare with Google Android.
- Can switch back easily and is very very unlikely you will brick the phone (cannot think of a way but people are creative)
- By using a VM you do not need anything new installed on your main PC. You can save/archive the VM to reuse anytime. It is best on the VM to use chrome as google likes it.
- Make sure you download everything before starting
- Virtual Box 6.1 with extension pack too
- Chrome setup
- Evaluation Win 10
- ADB files
- Google drivers
- UT installer
- You will not install anything on my local PC aside of Virtual Box (presume you have it already if you read this :))
Maybe a faster way to install for newcomers (all done for me in 20min.)
1.Install your VM with Windows 10 (get a free version from MS - https://info.microsoft.com/ww-landing-windows-10-enterprise.html - just fill in the form with whatever and download).
2. Enable USB access on the VM.
3. Test that you can see your Pixel on the VM.
3.a Start here : https://developers.google.com/android/images#sargo and get adb
3.b Get the Pixel drivers too https://developer.android.com/studio/run/win-usb
3.c Tip. May want to fiddle with the Virtual Box USB filters in VM ->Settings. The way your device is seen will change as you go thru the motions.
4. Use the google sargo page listed at 3a to flash the correct version as listed (currently is PQ3B.190801.002 - may change) on your VM. If it works you have a winning setup and your install will work for sure. If you have issues you can always restart the flash, so do no not worry. Always keep 3.c on the back of your mind.
5. This is your Go-No Go gateway. If your mobile flashed OK and you can see the Pixel3a on your Windows VM you ready to install Ubuntu Touch using the UBPorts executable (it has well documented requirements that I will not enumerate) on the VM. At the end of the process your USB filter will change again (see 3.c).
6. All worked OK for me - the only catch was with the HotSpot - needed to update the APN but I guess it was to be expected.
7. If you want to go back use the same VM and web page from 3a to flash whatever Android you want.