{
  "id": "etcd",
  "name": "etcd Node",
  "profile": "etcd",
  "selector": {
    "os": "installed"
  },
  "metadata": {
    "etcd_discovery": "KPC_discovery_token",
    "ssh_authorized_keys": ["KPC_ssh_authorized_keys"]
  }
}

{
  "id": "etcd",
  "name": "etcd Node",
  "profile": "etcd",
  "selector": {
    "os": "installed"
  },
  "metadata": {
    "etcd_discovery": "KPC_discovery_token",
    "coreos_private_subnet_hint": "KPC_private_subnet_hint",
    "ssh_authorized_keys": ["KPC_ssh_authorized_keys"]
  }
}

Simplify command and change to pulling var from bootcfg group instead of using substitution during deploy (2of2)
Simplify command and change to pulling var from bootcfg group instead of using substitution during deploy (2of2)

The substitution during deploy will happen here now. Will add aforementioned warning comment to deploy guide since I don't think I can put it here.