D2X's Release 2GP flow could be optimized by splitting into separate jobs. The advantages include:

1. Faster build times by running jobs in parallel
2. Better integration into GitHub's web user experience for viewing Actions Workflow executions
3. Retry only failed jobs instead of re-running everything (release promotion + test)

This sets up the reusable workflow as callable and requires the dev-hub-auth-url secret:

name: Release 2GP

on:
  workflow_call:
    secrets:
      dev-hub-auth-url:
        required: true

Then, everything runs serially in a single job:

jobs:
    release-test:
        name: "Release 2GP"
        runs-on: ubuntu-latest
        container:
            image: ghcr.io/muselab-d2x/d2x:latest
            options: --user root
            credentials:
                username: ${{ github.actor }}
                password: ${{ secrets.github-token }}
            env:
                DEV_HUB_AUTH_URL: "${{ secrets.dev-hub-auth-url }}"
        steps:
            - name: Checkout
              uses: actions/checkout@v2
            - name: Auth to DevHub
              run: /usr/local/bin/devhub.sh
            - name: Set default org
              run: cci org default release

The next step creates a scratch org and installs dependencies to prepare it for the release test:

            - name: Install Dependencies for Resolution
              run: cci flow run dependencies

Installing dependencies could happen in parallel with promoting and publishing the release to GitHub but we can't because we're stuck in a single job:

            - name: Promote Latest Beta
              run: cci flow run release_2gp_production
              shell: bash

Release testing could be faster if dependencies were preinstalling in parallel with release creation:

            - name: Run Release Test
              run: cci flow run ci_release

And finally, scratch org deletion would be nicer as its own Job in the GitHub Actions UI:

            - name: Delete Scratch Org
              if: ${{ always() }}
              run: |
                cci org scratch_delete release
              shell: bash