For a Job with parallelism > 1, how can pods have a unique label for selection

When running a batch v1 Job with parallelism greater than 1 and completionMode Indexed or NonIndexed, a pod cannot be specifically selected for the lack of a unique label. For Indexed completionMode, annonations like
batch.kubernetes.io/job-completion-index: “0”
batch.kubernetes.io/job-completion-index: “1”
are added to pods but no such labels
For NonIndexed, it would be helpful to be able to assign a label to each pod, say from a user provided list of labels.
Is there a way to do this or an alternative?