@luby
Hello,
I discover today your difficulties to install ubuntu touch on the nexus 7 flo. I propose you the procedure which allowed me to install UT on my nexus 7 flo. I attach my post dated November 14, 2020.

Hello to All,
After several months of failed installation of ubuntu touch on my nexus 7 flo, I come back to you to report the success (finally!) of the installation on my device.
To do this, I had to reinstall the stock version of android on the nexus 7.
While browsing xda developers, I found a tool to repair and factory reset the Nexus 7 2013: restock2.zip .
In addition to repair options, restock2 installs reliable usb drivers (my usb connection was unstable under xubuntu 20.04).
For installation and use you need a windows operating system.
Extract restock2.zip
Device plugged in and bootloader open, just double click on the "restock.bat" file and follow the whole installation procedure (well documented procedure on xda).
Resetting the device is quite long, you have to be patient...
With the rom stock open, you have to set up the develop mode.
Then ubports-installer does the job.
Not having much left to lose, I used this procedure "blind" and I am surprised and very satisfied with the result.
On the forums, I realized that I'm not the only one impacted by the difficulty of installing UT on nexus 7 flo ... If my experience as a novice can help some people, so much the better!
See you soon.

@Lakotaubp
Bonjour,
Thank you for this quick answer and for the translation of my "prose" .
I will implement your proposal to install a recent version of android.
Before installing /e/, my nexus 7 was running with an unofficial version of lineage os 17.1, so with android 10.
Before installing lineage os 17.1, I had to resize the partitions in twrp.
I will follow your advice and keep you informed.
This may help other people who are having trouble installing nexus flo.
Thank you for your help.

@luby
Hello,
I discover today your difficulties to install ubuntu touch on the nexus 7 flo. I propose you the procedure which allowed me to install UT on my nexus 7 flo. I attach my post dated November 14, 2020.

Hello to All,
After several months of failed installation of ubuntu touch on my nexus 7 flo, I come back to you to report the success (finally!) of the installation on my device.
To do this, I had to reinstall the stock version of android on the nexus 7.
While browsing xda developers, I found a tool to repair and factory reset the Nexus 7 2013: restock2.zip .
In addition to repair options, restock2 installs reliable usb drivers (my usb connection was unstable under xubuntu 20.04).
For installation and use you need a windows operating system.
Extract restock2.zip
Device plugged in and bootloader open, just double click on the "restock.bat" file and follow the whole installation procedure (well documented procedure on xda).
Resetting the device is quite long, you have to be patient...
With the rom stock open, you have to set up the develop mode.
Then ubports-installer does the job.
Not having much left to lose, I used this procedure "blind" and I am surprised and very satisfied with the result.
On the forums, I realized that I'm not the only one impacted by the difficulty of installing UT on nexus 7 flo ... If my experience as a novice can help some people, so much the better!
See you soon.

Hello,
Thank you for your involvement in finding solutions to my difficulties with UT.
In my last post, I indicated that I considered my problems as "solved" but, I was not precise enough. I was able to stably fix the libertine tweak-tool app for my container named "stock" (220 dpi) which allowed a better definition of the installed desktop apps. But, as I didn't know the doniks details, I didn't check if the line "Xft.dpi: 220" was in .../user-data/CONTAINERID. However, if desktop apps can be used, especially firefox, all menu bars are always displayed in lowercase; this may be a reference to the doniks details on the line Xft.dpi: 220 ?
Emanuele Sorce: the first time I used sturm reader, I activated the button at the bottom of the app and made the settings and font choices, but the margin slider had no effect on them; I add that the sturm-reader's welcome interface did not match the openstore app presentation (empty interface with the only indication to search for a book).
Faced with my difficulties, and before reading your last advice, I got discouraged (too fast?) and I ended up uninstalling UT from my nexus 7 to go back to my old rom (resurrection-remix) while waiting for better knowledge on my part in the use of UT .
Thanks again for your help.
Out of subject: when installing UT, ubports-installer asks for a confirmation of the device and indicates LG as the manufacturer of the nexus 7 flo. I would like to specify that the flo manufacturer is Asus and not lg...

Hello,
I managed to get a better definition of desktop applications by applying the libertine tweak-tool advice given by lowkeylone. I was able to install firefox in the container and it works fine.
On the other hand, the ebook layout issue in sturm-reader is still unresolved. Is this problem specific to the nexus 7 flo ?
Even if I don't have all the solutions to the exposed problems, I will indicate "solved" and put an end to my questions.
Thanks again for your help.

Hello,
Thank you both for your help.
lowkeylone: I applied your instructions but without any result. Set to 220 DPI or higher, there is no change. Moreover, when I close libertine-tweak-tool, all settings are erased; is this normal? Is the solution going through the terminal?

Emanuele Sorce: as soon as I installed UT, I installed the two apps you told me. But for both apps, I'm disappointed by the epub layout; the text doesn't fill the whole surface of the reader (large margins), despite the optimal settings (photo). That's why I decided to install destock apps (no luck there either...).
I add that two years ago, under UT 15.04, I had no problem with the beru app.
I'm aware that its problems are not easy to solve; this brings me back to my inexperience with UT 16.04 (I had to put my nexus back in stock version to install it successfully).
Thanks again for your help.

Translated with www.DeepL.com/Translator (free version)

Hello,
Thank you very much for your help. But, new to UT, I don't know how to exploit libertine-tweak-tool. I have enabled DPI setting and indicated a value but I guess it's not that simple; nothing happens for my two desktop apps (geary and fbreader), the definition remains the same. I'm attaching a screenshot.
If you have a little time, I'll take a little wiki. A solution would open many perspectives in the use of UT.
Thanks again.

Hello,
After installing a Libertine container on the nexus 7 flo, I installed the fbreader desktop application.
Problem: fbreader displays a minimum resolution that doesn't match the screen resolution of the nexus 7 flo (1920 x 1200).
Is there a solution to adapt fbreader to the screen resolution?
Thank you for your answer.

Hello to All,
After several months of failed installation of ubuntu touch on my nexus 7 flo, I come back to you to report the success (finally!) of the installation on my device.
To do this, I had to reinstall the stock version of android on the nexus 7.
While browsing xda developers, I found a tool to repair and factory reset the Nexus 7 2013: restock2.zip .
In addition to repair options, restock2 installs reliable usb drivers (my usb connection was unstable under xubuntu 20.04).
For installation and use you need a windows operating system.
Extract restock2.zip
Device plugged in and bootloader open, just double click on the "restock.bat" file and follow the whole installation procedure (well documented procedure on xda).
Resetting the device is quite long, you have to be patient...
With the rom stock open, you have to set up the develop mode.
Then ubports-installer does the job.
Not having much left to lose, I used this procedure "blind" and I am surprised and very satisfied with the result.
On the forums, I realized that I'm not the only one impacted by the difficulty of installing UT on nexus 7 flo ... If my experience as a novice can help some people, so much the better!
See you soon.

Good morning,
I made another attempt yesterday.
At first, the installation process is proceeding normally to arrive at this screen:
.
After all these procedural failures, I must reinstall twrp and my original rom each time.
I must admit that I am a bit discouraged, especially since I have been using xubuntu for many years and have installed ubuntu-touch on my tablet in the past without any problem (ota 7,8...).
Thank you again for the follow-up you are doing.

This is the terminal return:
ubports-installer
(process:4521): Gtk-WARNING **: 09:17:08.156: Locale not supported by C library.
Using the fallback 'C' locale.
(ubports-installer:4521): GdkPixbuf-WARNING **: 09:17:08.420: Cannot open pixbuf loader module file '/usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders.cache': No such file or directory
This likely means that your installation is broken.
Try running the command
gdk-pixbuf-query-loaders > /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders.cache
to make things work again for the time being.
info: Welcome to the UBports Installer version 0.4.18-beta!

doniks:
"LG" is fine. LG is who manufactured it for Google. That is all still "flo"

Thank you for your response.
I wish to make a correction concerning the manufacturer of the google nexus 7 2013 wifi flo.
It is not LG but Asus. The code name is asus-flo.
Again, I do not know if this "detail" is important.
Good day; in France it is 9 o'clock.