From their repo:
Plasma Login
Plasma Login provides a display manager for KDE Plasma, forked from SDDM and with an new frontend providing a greeter, wallpaper plugin integration and System Settings module (KCM).
What we want
- Great out-of-box experience in multi-monitor and high DPI and HDR
- Keyboard layout switching
- Virtual keyboards
- Easy Chinese/Japanese/Korean/Vietnamese (CJK) input
- Screen readers for blind people (which then means volume control)
- Remote (VNC/RDP) support from startup
- Deeper Plasma integration including:
- Display and keyboard brightness control
- Full power management
- Pairing trusted bluetooth devices
- Login to known Wi-Fi for remote LDAP
I upgraded from 42 to 43 through discover. I think that and terminal are the recommended methods, according to the docs. If you do it with ISO it writes over the root partition and keeps all other partitions and volumes.