Hi, sorry I don't know.
I don't own this phone and from what I can read here Xiaomi are well supported, but are a pain in the butt to install at first.
I'd say, if you already have this device you can try to install Ubuntu Touch and see if it fails 🤷♂
If you don't have the device yet, I'd suggest to opt for other device but it will depend deeply on your needs and how you feel about the installation effort.
@loganj hm, installing firefox-esr just does not work... no idea why.
Regarding your dream:
In theory it is totally possible to install and use some desktop applications if they are availabe for arm(64).
Practically there will be some drawbacks, like drm-video-streams will not work for example. At least, I don't know of anyone who managed to watch Netflix or similar on an Ubuntu Touch device.
@carlod Some people claim that the files on the 'persist' (ext4) and 'persist_image' (emmc) partitions were changed, but I saved and restored those too. So something else. Maybe some code inside in the WiFi chip (Qualcomm) ? Unfortunately I do not know yet in detail how it works.
@lakotaubp I had the same problem. I think it's because I installed the wrong Jasmine sprout image found on the internet. The only fix I've found is to get the A2 back to factory setup, using the Mi restore tool, and then do it all again from the start.
Using the link to the jasmine sprout found on the UBports installer, hasn't put back the tux on my fastboot anyway ...