I've been playing around with Peppermint OS and found an issue with the LibreOffice file dialogs.
The LibreOffice File > Open, File > Save dialogs don't include useful things like mounted USB memory sticks, network links or any bookmarks that you would find in the system file manager.
You get the same dreadful dialogs in Lubuntu if you set the "Use LibreOffice dialogue boxes" option in LibreOffice.
why Peppermint OS?
I have been looking to convert my wife's laptop from Ubuntu to something less infuriating for some time. The Peppermint operating system is a little more polished than Lubuntu, but is equally simple in layout and use. I also wanted to investigate Peppermint's single site browser (SSB) system as I'm not getting a good feeling about my Lubuntu system since they dropped Midori from the repository.
Peppermint includes an SSB system that they call ICE. This sounds ideal for each of my banking websites, and possibly as a way of putting FaceAche in its own sandbox.
On Peppermint v8 & v9 the LibreOffice Save dialog looks like this:-
This file dialog has a Places pane which does not include the bookmarks or devices from the system file manager. So if you want to open or save a file to a memory stick you have to navigate the file system and look for it in the /media folder. You can't expect a non-teckie user to do this, or a teckie user to put up with it. This was what Linux looked like 20 years ago!
The solution is to open Synaptic and install:-
I think I had to re-boot to get this change to take affect, but this then gives you the option in LibreOffice to turn off LibreOffice dialog boxes via: menu Tools > Options... > General > Open/Save dialogue boxes > then disable Use LibreOffice dialogue boxes
Now your file dialog boxes should look like this:-