In reading the Plugin README, it says:

Enable SSH for all users
Go to System Preferences -> Sharing, and enable Remote Login for All users :

and:

Configure a Jenkins User
Create an user on the Mac with administrator privilege

Would it not be preferred to restrict SSH to the specific user(s) which would be running the agents and to run them with less than Admin privileges.

I am not a well-versed Mac User, but the *nix build agents can be launched as any user, so why not grant the lowest reasonable level access? In the alternative, at least explain WHY it's necessary to configure with such elevated privileges such that fair consideration can be applied to using the plugin.