I am able to get the plugin working (not extensive testing) with a combo of regular and backports packages versions hard-coded as dependencies in the plugin. I haven't tested from a clean install or an existing install. My test was from a system that had packages installed and uninstalled many times. So, this might be missing something. If someone wants to try this, be my guest. You will have to be careful installing updates until the Debian repos are fixed.
# Make sure backports are enabled
wget https://omv-extras.org/testing/openmediavault-kvm_6.1.23_all.deb
sudo dpkg -i openmediavault-kvm_6.1.23_all.deb
sudo apt-get -f install