Hello,
I'm the developer of CloneDeploy. The plugin was pulled a while back after the Coral fiasco. Until I get sense of where FreeNAS is heading, I've stopped development specifically for FreeNAS. I don't know if they are continuing with plugins or moving to Docker eventually. I'm not sure where you got the plugin, maybe sourceforge? But it is very outdated. Now that FreeNAS supports VM's, that is what I would use, and is personally how I do it. There is also Docker support for CloneDeploy if you can manage getting that installed on FreeNAS.