Even though NFD Operator does allow to be installed into another namespace instead of openshift-nfd, it won't work as certain components won't work as openshift-nfd has for example hard-coded settings in ServiceMonitor requiring openshift-nfd namespace.

 - According to documentation it should be installed into openshift-nfd
   but still OLM offers to select another namespace which then will break
   certain functionality.

In addition to that openshift-nfd creates two identical ServiceMonitor during the installation which are likely not required and referencing openshift-nfd namespace (hence removing flexibility with variable namespace).

$ oc get servicemonitor
NAME                                     AGE
controller-manager-metrics-monitor       13m
nfd-controller-manager-metrics-monitor   13m

$ oc get servicemonitor -o yaml
apiVersion: v1
items:
- apiVersion: monitoring.coreos.com/v1
  kind: ServiceMonitor
  metadata:
    creationTimestamp: "2023-01-10T15:04:44Z"
    generation: 1
    labels:
      control-plane: controller-manager
    name: controller-manager-metrics-monitor
    namespace: openshift-nfd
    ownerReferences:
    - apiVersion: operators.coreos.com/v1alpha1
      blockOwnerDeletion: false
      controller: false
      kind: ClusterServiceVersion
      name: nfd.4.11.0-202212070335
      uid: d32aa098-cc0b-4fbd-8189-f15cb6961e8b
    resourceVersion: "620263"
    uid: c4ffc0e2-1fe2-40df-9ac1-551c083ad76c
  spec:
    endpoints:
    - bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
      interval: 30s
      path: /metrics
      port: https
      scheme: https
      tlsConfig:
        caFile: /etc/prometheus/configmaps/serving-certs-ca-bundle/service-ca.crt
        serverName: nfd-controller-manager-metrics-service.openshift-nfd.svc
    selector:
      matchLabels:
        control-plane: controller-manager
- apiVersion: monitoring.coreos.com/v1
  kind: ServiceMonitor
  metadata:
    creationTimestamp: "2023-01-10T15:04:46Z"
    generation: 1
    labels:
      control-plane: controller-manager
    name: nfd-controller-manager-metrics-monitor
    namespace: openshift-nfd
    ownerReferences:
    - apiVersion: operators.coreos.com/v1alpha1
      blockOwnerDeletion: false
      controller: false
      kind: ClusterServiceVersion
      name: nfd.4.11.0-202212070335
      uid: d32aa098-cc0b-4fbd-8189-f15cb6961e8b
    resourceVersion: "620354"
    uid: 51193fb4-01eb-475e-a3b2-564736b53383
  spec:
    endpoints:
    - bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
      interval: 30s
      path: /metrics
      port: https
      scheme: https
      tlsConfig:
        caFile: /etc/prometheus/configmaps/serving-certs-ca-bundle/service-ca.crt
        serverName: nfd-controller-manager-metrics-service.openshift-nfd.svc
    selector:
      matchLabels:
        control-plane: controller-manager
kind: List
metadata:
  resourceVersion: ""

4.11.20

Always

1. Install OpenShift Container Platform 4
2. Install Node Feature Discovery Operator
3. Select another namespace but openshift-nfd
4. See ServiceMonitor created with reference to openshift-nfd

openshift-nfd is required as namespace even though another can be selected and two identical ServiceMonitor are being created.

Either remove flexibility to install NFD Operator into non openshift-nfd namespace or otherwise remove hard-coded references to openshift-nfd namespace.

Remove the two identical ServiceMonitor