Comment 8 for bug 1987644

IdMServer and IdMDomain are not rendered into inventory but into the playbook generated by config download. Once you set both these two parameters, you see these values are defined in a playbook yaml file under the config-download directory.

Because the problem was resolved by setting both IdMServer and IdMDomain, which looks the expected way to override the ipaclient_domain parameter, I'd close this as invalid but let me know in case you have any concern.