Hi Didier, just a quick review of the recent Slint 15.0 RC, it was quick because my son is all over me  
 
   
   
 
Slint boots fine, hit Enter at Grub and selected Portuguese (Portugal) wich also work fine  
 
 
Booting from Slint I always get this message:
Loading the kernel and installer initrd. Please wait...
vga=normal is deprecated. useset gfxpayload=text before linux command instead.
It doesn't interfere in any way, but just for the record.
In the welcome screen(console)
Typing 
doc everything works great and the documentation is in Portuguese, went to the bottom of the documentation with the arrow key to read all and then hit 
q to quit and go back to the previous screen.
Then type 
start to begin the installation and choose 
auto pressing 
a.
Choose the all 149GB of the HDD to root partition. This was what i get:
 
Passwords and user name creation all works great.
Wi-Fi detection also works great but before the installation it tries to get the latest packages and i got i quick error about saying os-prober-181... or something is corrupted... It was fast and I don´t catch all... 
 
 
However, Slint installer begins installing the packages....
Choose install with a description per line....
All went well but i saw this 
$pkgname thing instead of the name of the package...
 
It was nice to see that 
libreoffice-l10n-pt Portuguese and 
aspell-pt_PT were installed by default.
In the end of the installation when choosing the 
desktop environment/Window manager this appears:
......
fvwm
lxqt
mate
wmaker
A sua escolha: lxqt  <-- (in Portuguese, my desktop choice)
lxqt has been chosen.
Running update_all. Please be patient...
The last text, after 
lxqt is in English.... is this normal?
Anyway, the installation is very intuitive  
 
 
I restarted the system....
First boot went well
In ligthdm-greeter:
 
because of:
 
Edit the lightdm-greeter to become more centered:
 
Both 
mate and 
lxqt performs well, just needs a little tweaking in appearance and everything is to our liking.
For e.g this mixture of dark with light in 
lxqt not the most pleasant to look at by default:
 
Some more screenshots...
LXQt
 
 mate
mate
 
 
Typing 
slint-doc pt_PT in the terminal:  
 
 
 
If I have time I will try to report any bugs I find....
Cheers