Identify correct usage measures for devops:release

Looker has a great new report (https://app.periscopedata.com/app/gitlab/425984/Month-over-Month-Overstimated-SMAU) showing usage of each of the stages, and how that's changing over time:

Usage for ~Release users is determined using the following query (in https://gitlab.looker.com/projects/gitlab/files/usage_data.view.lkml):

  measure:  release_users{
    type: count_distinct
    group_label: "Product Stages"
    label: "Count of Release Users"
    sql:
       CASE WHEN ${releases} > 0
                 OR ${in_review_folder} > 0
                 OR ${pages_domains} > 0
                 OR ${ci_deployments} > 0
                 OR ${environments} > 0
       THEN ${host_id}
       ELSE NULL
       END ;;
  }

So two questions here - what measures are missing that already exist, and what measures should be added to get an accurate assessment?