How ubuntu auto recovers from an interrupted (blackout) system update (not OS Version upgrade)? Mainly about kernel updates

Question

In this question, I don't want to know how I can manually recover from that problem.
I already use this workaround: https://unix.stackexchange.com/a/626503/30352 (and I also have another HD with an older OS ready to boot to perform that whole system recovery).

I am talking about packages updates (mostly kernel, but not only it) without increasing the OS version.

So, does ubuntu auto recovers at all?
If so, how it does that?

It is very hard to search about it on google as almost everything is about system UPGRADE and not UPDATE (that does not changes the OS version), and most critically when these are about the kernel and the boot files...

---

I was thinking it could be something like this:

• safely write a config file saying everything will be done
• prepare all the packages to begin installing and set a flag when it completes
• install one package, and set a flag about it, and so on for each package
• configure one package, and set a flag about it, and so on for each package
• when it ends, set another flag saying installation completed successfully.

Then the flags would be used like this:

• the system will reboot using the previous working kernel
• will check if there was something being installed
• will check where it stopped and re-do that specific work (alternativelly could allow the user to let everything be reinstalled from the beggining using the downloaded packages or re-download them)
• All that would be done BEFORE completing the boot where the user could things manually, that would be an automatic CONTINUE_INSTALLING to recover from a blackout (or any other hardware, or even software, failure).

So, have you had that problem that may scare most desktop PC users that have no nobreak? If so, what happened to you ? (put that in comments)
And how ubuntu dealed with that problem in a technical way (but not necessarily too detailed way)? (put that as answer)

This question may feel like a forum post, but I am asking for technical (but not too much) details on how it happens, just the overlook, what steps it does like the ones I imagine it could do.
Also I think it is of utmost importance, as avoiding system updates leaves our machines unprotected from hackers (despite I already use the workaround, but I used to not update at all before doing that).