Hi there. Author of said inventory plugin.
If you ever wish to migrate you should be able to retain most of what you did on XOA side (I'm thinking tags), but you'll have something that's more standard and require less setup as long as the XOA API is accessible to the machine running the playbook.
You can keep the groups with the composable groups in your inventory plugin configuration:
simple_config_file:
plugin: community.general.xen_orchestra
api_host: 192.168.1.255
user: xo
password: xo_pwd
validate_certs: true
use_ssl: true
groups:
kube-master: "name_label == 'kube-master'"
compose:
ansible_port: 2222