An updated qt5 in CentOS Stream 8 allowed us to update KDE Plasma Desktop.
I believe everything is in place and ready for use and/or testing.
This is for CentOS Stream 8 only, at this time.
===How to Install 
= Install epel-release
dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
= Enable PowerTools
dnf config-manager --enable powertools
= Install KDE
dnf group install kde-desktop-environment
dnf group install kde-desktop
(Optional) dnf group install kde-apps
(Optional) dnf group install kde-media
(Optional) dnf group install kde-education
(Optional) dnf install okular
(Optional) dnf group install kde-software-development
(Optional) dnf group install kf5-software-development
=== KNOWN PACKAGE ISSUES
== UNINSTALLABLE PACKAGES
* kaccounts-providers - no signon-ui
* kigo - no gnugo
* lokalize - no translate-toolkit , needs rebuilding on python3
* polkit-qt5 - need branch and build of polkit-qt-1
* kde-gtk-config - needs sassc
* digikam - can't find opencv despite it being installed
== UN-UPDATED PACKAGES (but still install and run)
* kpmcore - would need a newer util-linux than available in RHEL 8
* kde-partitionmanager - would need a newer kpmcore
Feel free to install and test.