This script will create a local LXD image that has a full KDE desktop environment with Xspice as the display server.
./setup-debian-kde-desktop-xspice.sh
lxc init debian-kde-desktop-xspice kde
lxc config device add kde xspicesocket proxy bind=host listen=unix:/tmp/kde.unix connect=unix:/run/xspice/spice.unix uid=1000 gid=1000
lxc start kde