oc-mirror with v2 will create the idms file as output , but the source is like :
apiVersion: config.openshift.io/v1
kind: ImageDigestMirrorSet
metadata:
  creationTimestamp: null
  name: idms-2024-01-08t04-19-04z
spec:
  imageDigestMirrors:
  - mirrors:
    - ec2-3-144-29-184.us-east-2.compute.amazonaws.com:5000/ocp2/openshift
    source: localhost:55000/openshift
  - mirrors:
    - ec2-3-144-29-184.us-east-2.compute.amazonaws.com:5000/ocp2/openshift-release-dev
    source: quay.io/openshift-release-dev
status: {}

The source should always be the origin registry like :quay.io/openshift-release-dev

always  

   1. run the command with v2 :
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  platform:
    channels:
      - name: stable-4.14
        minVersion: 4.14.3
        maxVersion: 4.14.3
    graph: true

`oc-mirror --config config.yaml file://out --v2` 
`oc-mirror --config config.yaml --from file://out  --v2 docker://xxxx:5000/ocp2`    
2. check the idms file 

    2. cat idms-2024-01-08t04-19-04z.yaml 
apiVersion: config.openshift.io/v1
kind: ImageDigestMirrorSet
metadata:
  creationTimestamp: null
  name: idms-2024-01-08t04-19-04z
spec:
  imageDigestMirrors:
  - mirrors:
    - xxxx.com:5000/ocp2/openshift
    source: localhost:55000/openshift
  - mirrors:
    - xxxx.com:5000/ocp2/openshift-release-dev
    source: quay.io/openshift-release-dev

The source should not be localhost:55000, should be like the origin registry.