With the release today of Plasma 5.24.90 (5.24 Beta), testing for the next major Plasma version has started. Final release is planned for three weeks from now.
As always, place kde-next above all in your pacman.conf. If you do not know how to edit pacman.conf, then please don't try to attempt testing betas of Plasma, editing the pacman.conf is the easiest part of this kind of testing.

An ISO with Plasma 5.25 Beta is now also up:
https://sourceforge.net/projects/kaos-test/files/iso/KaOS-2022.05.21-x86_64.iso

Just use it to test Plasma in Live mode, best not use it (yet) for an install. There are some known bugs on it, part to do with the Plasma 5.25 changes, part to do with this first ISO build on the new toolchain and part because the installer is build with a new (partitionq) module. That module is not activated, but still runs on starting the installer (in the background).

13 days later

The default theme for KaOS, Midna, needed some adjusting to work with Plasma 5.25. That meant also implementing some changes, like better integration of the virtual-keyboard for both sddm & the lockscreen.
New way for both (with virtual-keyboard active):
Lockscreen:

SDDM:

11 days later