This is major because it caused data loss, and also an enhancement request.

Hello.
This applies to Calc and Writer alike.

I have checked the option that my documents will be saved every minutes.
After a BSOD, hours of work were lost as LibreOffice was unable to restore my document. I searched the whole hard drive for recently changed data. 
I did a test by killing the .bin file in taskmanager, and autosave did work then. However sometimes it does NOT seem to work and the user is left with NO fallback if relies on what the option advertises by stating that data will be saved every few minutes. A decent Office Suite should autosave every minute, without any impact / stuttering whilst editing, and not require to user to manually save at any point in time (which is very annoying). In fact, many Apps in iOS, and also my Windows Text editor of choice, autosave INSTANTLY.
I have had problems with auto-restore with OpenOffice (sic) too, years ago, and I really think that this feature needs to be as robust as possible.
I would like to see several fully functional backup files that are not more than 1-2 minutes old, in the libre office system folders, so users always have a simple fallback if any kind of corruption occurs. For example:
mytable.odt.bak1 (0-1 minute old)
mytable.odt.bak2 (1-2 minutes old)
mytable.odt.bak3 (2-3 minutes old)

every 1 minute, bak1 is renamed to bak2, bak2 to bak3, and a new bak1 is created.

(this could be done in the background by using accumulated delta data so ediging of the currently opened file will not be impacted - I am not a programmer, I hope you get what I mean)

This system (bak1/bak2/bak3) will also allow backup programs to access the current and backup files and create more sophisticated versioned backups, such as e.g.
1 minute ago
2
5 
10
20
30
40
60
2 hrs
4 hrs
8 hrs
12
16
...
7 days
8 days
9 days
etc.

please take this seriously. users must be protected from data loss at all cost. I found several users who seem to have had similar issues. please don't ignore this because it goes against some "philosophy" or because it is not "elegant" or because users should "press ctrl-s". what counts is that even the most ignorant users need to protected. the data lost can be invaluable in some cases. 

thank you.