You can find Containers and QXDiaplay here in op - Aarch64 RPMs (share) - #38 by Levone1 and to get desktop to work on 4.x you need QXCompositor, which is in the same thread, bit I couldn’t add it to op because locked. Just scroll down near the end…
Note that launching XSession from Containers app doesn’t work anymore, but you can still use it to create/start/stop/attach lxc, and then you can use QXC to create display, /usr/bin/qxcompositor -o portrait --wayland-socket-name "../../display/wayland-container-0" &
and then run desktop script to open desktop…