So my critical quick opinion after checking another Plasma5 distro in VM:
If you boot from ISO, hit -> change language - first two options are NOT translated.
In Oracle VirtualBox VM ‘Feren OS ISO’ boots to 800x600 res. and you get bigger window than screen resolution. You can’t change resolution from systemsettings5 or with “xrandr” terminal command because of a bug:
(you can change virtual graphics controller from ‘VMWARE’ to something else but then you loose “3D” option)
This is important bug, hits so many people on different distros and… is ignored by KDE devs.
You’ve chosen mintUpdate which has weird bug (probably Gtk specific) - during update sometimes small window pops up with info about file overwrite and then in this window you can click to see file differencies. But there is a problem with size of a field showing file contents - only two lines and can’t increase so it’s practically useless.
You’re using Qt5.13.2 and lightdm instead od SDDM but there is also this bug:
During running mintUpdate if you log out and click Power icon in up-right screen corner to shutdown then you get confirmation question but without big [Restart] and [Turn off] buttons.
In systemsettings5 - user settings you can’t change auto-login for a user because of this bug
Jesus - this is over FIVE years old bug - what the hell they are (NOT) doing out there?!
There is a problem with Oxygen widget style - if you have already selected this style and then go to its option, adjust scrollbar width, close settings windows then [Apply] button is not activated. You must again select Oxygen from the list and [Apply] button is active.
So, your distro suffers from many KDE specific bugs and worse, these bugs are unresolved for so long period of time; maybe “classic” Cinnamon is more polished and better choice…