Well I installed (eventually) 16 Core r1 and this is it with KDE dekstop:
Cursor size change in this manner:
Added Windows 11 Menu in KDE:
Windows 11 OS Theme.
New Wallpaper - Darkest Hour (especially if you are using Windows 11 .)
Proof this is on Zorin 16 Core r1:
I installed KDE via the terminal using:
sudo apt-get install kde-full