diff --git a/.github/workflows/staging-build-pr.yml b/.github/workflows/staging-build-pr.yml
index e73a77d33d..9263188b36 100644
--- a/.github/workflows/staging-build-pr.yml
+++ b/.github/workflows/staging-build-pr.yml
@@ -15,6 +15,14 @@ permissions:
   contents: read
 
 jobs:
+  debug:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Dump full context for debugging
+        env:
+          GITHUB_CONTEXT: ${{ toJSON(github) }}
+        run: echo "$GITHUB_CONTEXT"
+
   build-pr:
     if: ${{ github.repository == 'github/docs-internal' || github.repository == 'github/docs' }}
     runs-on: ubuntu-latest
diff --git a/.github/workflows/staging-deploy-pr.yml b/.github/workflows/staging-deploy-pr.yml
index 918cafff5c..cb8118a4df 100644
--- a/.github/workflows/staging-deploy-pr.yml
+++ b/.github/workflows/staging-deploy-pr.yml
@@ -19,48 +19,116 @@ permissions:
   statuses: write
 
 env:
-  # In this specific workflow relationship, the `github.event.workflow_run.pull_requests`
-  # array will always contain only 1 item! Specifically, it will contain the PR associated
-  # with the `github.event.workflow_run.head_branch` that triggered the preceding
-  # `pull_request` event that triggered the "Staging - Build PR" workflow.
-  # WARNING: However, it will contain 0 items if the associated PR has been closed.
-  PR_NUMBER: ${{ github.event.workflow_run.pull_requests[0].number || '0' }}
-  PR_URL: ${{ github.event.workflow_run.repository.html_url }}/pull/${{ github.event.workflow_run.pull_requests[0].number }}
   CONTEXT_NAME: '${{ github.workflow }} / deploy (${{ github.event.workflow_run.event }})'
   ACTIONS_RUN_LOG: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
+  BUILD_ACTIONS_RUN_ID: ${{ github.event.workflow_run.id }}
   BUILD_ACTIONS_RUN_LOG: https://github.com/${{ github.repository }}/actions/runs/${{ github.event.workflow_run.id }}
-  HEAD_SHA: ${{ github.event.workflow_run.head_sha }}
 
 jobs:
   debug:
     runs-on: ubuntu-latest
     steps:
-      - name: Dump info about the originating workflow run
-        env:
-          PR_NUMBER: ${{ env.PR_NUMBER }}
-          PR_URL: ${{ env.PR_URL }}
-          HEAD_SHA: ${{ env.HEAD_SHA }}
-          HEAD_REF: ${{ github.event.workflow_run.head_branch }}
-          BUILD_ACTIONS_RUN_ID: ${{ github.event.workflow_run.id }}
-          BUILD_ACTIONS_RUN_LOG: ${{ env.BUILD_ACTIONS_RUN_LOG }}
-        run: |
-          echo "Originating workflow info:"
-          echo " - PR_NUMBER = $PR_NUMBER"
-          echo " - PR_URL = $PR_URL"
-          echo " - HEAD_SHA = $HEAD_SHA"
-          echo " - HEAD_REF = $HEAD_REF"
-          echo " - BUILD_ACTIONS_RUN_ID = $BUILD_ACTIONS_RUN_ID"
-          echo " - BUILD_ACTIONS_RUN_LOG = $BUILD_ACTIONS_RUN_LOG"
-
       - name: Dump full context for debugging
         env:
           GITHUB_CONTEXT: ${{ toJSON(github) }}
         run: echo "$GITHUB_CONTEXT"
 
+  pr-metadata:
+    runs-on: ubuntu-latest
+    outputs:
+      number: ${{ steps.pr.outputs.number }}
+      url: ${{ steps.pr.outputs.url }}
+      state: ${{ steps.pr.outputs.state }}
+      head_sha: ${{ steps.pr.outputs.head_sha }}
+      head_ref: ${{ steps.pr.outputs.head_ref }}
+    steps:
+      - name: Find the originating pull request
+        id: pr
+        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
+        env:
+          BUILD_ACTIONS_RUN_ID: ${{ env.BUILD_ACTIONS_RUN_ID }}
+        with:
+          script: |
+            // In order to find out the PR info for a forked repo, we must query
+            // the API for more info based on the originating workflow run
+            const { BUILD_ACTIONS_RUN_ID } = process.env
+            const { owner, repo } = context.repo
+            const { data: run } = await github.actions.getWorkflowRun({
+              owner,
+              repo,
+              run_id: BUILD_ACTIONS_RUN_ID,
+            })
+
+            // Gather PR-identifying information from the workflow run
+            const {
+              head: {
+                label: headLabel,
+                ref: headBranch,
+                sha: headSha,
+                repo: {
+                  owner: { login: prRepoOwner },
+                  name: prRepoName
+                }
+              }
+            } = run
+
+            const prIsInternal = owner === prRepoOwner && repo === prRepoName
+
+            // If the PR is external, prefix its head branch name with the
+            // forked repo owner's login, e.g. "octocat:docs"
+            const headRef = prIsInternal ? headBranch : headLabel
+
+            // Retrieve matching PRs (up to 30)
+            const { data: pulls } = await github.pulls.list({
+              owner,
+              repo,
+              head: headLabel,
+              sort: 'updated',
+              direction: 'desc',
+              per_page: 30
+            })
+
+            // Find the open PR, if any, otherwise choose the most recently updated
+            const targetPull = pulls.find(pr => pr.state === 'open') || pulls[0] || {}
+
+            const pullNumber = targetPull.number || 0
+            const pullUrl = targetPull.html_url || 'about:blank'
+            const pullState = targetPull.state || 'closed'
+
+            core.setOutput('number', pullNumber.toString())
+            core.setOutput('url', pullUrl)
+            core.setOutput('state', pullState)
+            core.setOutput('head_sha', headSha)
+            core.setOutput('head_ref', headRef)
+
+  debug-originating-trigger:
+    needs: pr-metadata
+    runs-on: ubuntu-latest
+    steps:
+      - name: Dump info about the originating workflow run
+        env:
+          PR_NUMBER: ${{ needs.pr-metadata.outputs.number }}
+          PR_URL: ${{ needs.pr-metadata.outputs.url }}
+          PR_STATE: ${{ needs.pr-metadata.outputs.state }}
+          HEAD_SHA: ${{ needs.pr-metadata.outputs.head_sha }}
+          HEAD_REF: ${{ needs.pr-metadata.outputs.head_ref }}
+          BUILD_ACTIONS_RUN_ID: ${{ env.BUILD_ACTIONS_RUN_ID }}
+          BUILD_ACTIONS_RUN_LOG: ${{ env.BUILD_ACTIONS_RUN_LOG }}
+        run: |
+          echo "Originating workflow info:"
+          echo " - PR_NUMBER = $PR_NUMBER"
+          echo " - PR_URL = $PR_URL"
+          echo " - PR_STATE = $PR_STATE"
+          echo " - HEAD_SHA = $HEAD_SHA"
+          echo " - HEAD_REF = $HEAD_REF"
+          echo " - BUILD_ACTIONS_RUN_ID = $BUILD_ACTIONS_RUN_ID"
+          echo " - BUILD_ACTIONS_RUN_LOG = $BUILD_ACTIONS_RUN_LOG"
+
   notify-of-failed-builds:
+    needs: pr-metadata
     if: >-
       ${{
-        (github.event.workflow_run.pull_requests[0].number || '0') != '0' &&
+        needs.pr-metadata.outputs.number != '0' &&
         github.event.workflow_run.conclusion == 'failure' &&
         (github.repository == 'github/docs-internal' || github.repository == 'github/docs')
       }}
@@ -73,14 +141,14 @@ jobs:
         id: check-workflow-run
         uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
         env:
-          BUILD_RUN_ID: ${{ github.event.workflow_run.id }}
+          BUILD_ACTIONS_RUN_ID: ${{ env.BUILD_ACTIONS_RUN_ID }}
         with:
           script: |
             const { owner, repo } = context.repo
             const { data: { jobs: buildJobs } } = await github.actions.listJobsForWorkflowRun({
               owner,
               repo,
-              run_id: process.env.BUILD_RUN_ID,
+              run_id: process.env.BUILD_ACTIONS_RUN_ID,
               filter: 'latest'
             })
             const wasCancelled = (
@@ -98,19 +166,20 @@ jobs:
           channel: ${{ secrets.DOCS_STAGING_DEPLOYMENT_FAILURES_SLACK_CHANNEL_ID }}
           bot-token: ${{ secrets.SLACK_DOCS_BOT_TOKEN }}
           color: failure
-          text: Staging build failed for PR ${{ env.PR_URL }} at commit ${{ env.HEAD_SHA }}. See ${{ env.BUILD_ACTIONS_RUN_LOG }}. This run was ${{ env.ACTIONS_RUN_LOG }}.
+          text: Staging build failed for PR ${{ needs.pr-metadata.outputs.url }} at commit ${{ needs.pr-metadata.outputs.head_sha }}. See ${{ env.BUILD_ACTIONS_RUN_LOG }}. This run was ${{ env.ACTIONS_RUN_LOG }}.
 
   check-pr-before-prepare:
+    needs: pr-metadata
     if: >-
       ${{
-        (github.event.workflow_run.pull_requests[0].number || '0') != '0' &&
+        needs.pr-metadata.outputs.number != '0' &&
         github.event.workflow_run.conclusion == 'success' &&
         (github.repository == 'github/docs-internal' || github.repository == 'github/docs')
       }}
     runs-on: ubuntu-latest
     timeout-minutes: 1
     concurrency:
-      group: staging_${{ github.event.workflow_run.head_branch }}
+      group: 'staging_${{ needs.pr-metadata.outputs.head_ref }}'
       cancel-in-progress: true
     outputs:
       pull_request_state: ${{ steps.check-pr.outputs.state }}
@@ -119,7 +188,7 @@ jobs:
         id: check-pr
         uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
         env:
-          PR_NUMBER: ${{ env.PR_NUMBER }}
+          PR_NUMBER: ${{ needs.pr-metadata.outputs.number }}
         with:
           script: |
             const { owner, repo } = context.repo
@@ -131,12 +200,12 @@ jobs:
             core.setOutput('state', pullRequest.state)
 
   prepare-for-deploy:
-    needs: check-pr-before-prepare
+    needs: [pr-metadata, check-pr-before-prepare]
     if: ${{ needs.check-pr-before-prepare.outputs.pull_request_state == 'open' }}
     runs-on: ubuntu-latest
     timeout-minutes: 5
     concurrency:
-      group: staging_${{ github.event.workflow_run.head_branch }}
+      group: 'staging_${{ needs.pr-metadata.outputs.head_ref }}'
       cancel-in-progress: true
     outputs:
       source_blob_url: ${{ steps.build-source.outputs.download_url }}
@@ -146,7 +215,7 @@ jobs:
         env:
           CONTEXT_NAME: ${{ env.CONTEXT_NAME }}
           ACTIONS_RUN_LOG: ${{ env.ACTIONS_RUN_LOG }}
-          HEAD_SHA: ${{ env.HEAD_SHA }}
+          HEAD_SHA: ${{ needs.pr-metadata.outputs.head_sha }}
         with:
           script: |
             const { CONTEXT_NAME, ACTIONS_RUN_LOG, HEAD_SHA } = process.env
@@ -188,14 +257,14 @@ jobs:
         run: node script/early-access/clone-for-build.js
         env:
           DOCUBOT_REPO_PAT: ${{ secrets.DOCUBOT_REPO_PAT }}
-          GIT_BRANCH: ${{ github.event.workflow_run.head_branch }}
+          GIT_BRANCH: ${{ needs.pr-metadata.outputs.head_ref }}
 
       # Download the previously built "app.tar"
       - name: Download build artifact
         uses: dawidd6/action-download-artifact@b9571484721e8187f1fd08147b497129f8972c74
         with:
           workflow: ${{ github.event.workflow_run.workflow_id }}
-          run_id: ${{ github.event.workflow_run.id }}
+          run_id: ${{ env.BUILD_ACTIONS_RUN_ID }}
           name: pr_build
           path: ./
 
@@ -217,12 +286,8 @@ jobs:
           mv content/early-access "$RUNNER_TEMP/content/"
           mv data/early-access "$RUNNER_TEMP/data/"
 
-      - name: Create an updated archive
-        run: tar -c --file app.tar "$RUNNER_TEMP/"
-
-      # Create "app.tar.gz" and delete "app.tar"
       - name: Create a gzipped archive
-        run: gzip app.tar
+        run: tar -cz --file app.tar.gz "$RUNNER_TEMP/"
 
       - name: Install Heroku client development-only dependency
         run: npm install --no-save heroku-client
@@ -275,7 +340,7 @@ jobs:
         env:
           CONTEXT_NAME: ${{ env.CONTEXT_NAME }}
           ACTIONS_RUN_LOG: ${{ env.ACTIONS_RUN_LOG }}
-          HEAD_SHA: ${{ env.HEAD_SHA }}
+          HEAD_SHA: ${{ needs.pr-metadata.outputs.head_sha }}
         with:
           script: |
             const { CONTEXT_NAME, ACTIONS_RUN_LOG, HEAD_SHA } = process.env
@@ -297,14 +362,14 @@ jobs:
           channel: ${{ secrets.DOCS_STAGING_DEPLOYMENT_FAILURES_SLACK_CHANNEL_ID }}
           bot-token: ${{ secrets.SLACK_DOCS_BOT_TOKEN }}
           color: failure
-          text: Staging preparation failed for PR ${{ env.PR_URL }} at commit ${{ github.event.workflow_run.head_sha }}. See ${{ env.ACTIONS_RUN_LOG }}
+          text: Staging preparation failed for PR ${{ needs.pr-metadata.outputs.url }} at commit ${{ needs.pr-metadata.outputs.head_sha }}. See ${{ env.ACTIONS_RUN_LOG }}.
 
   check-pr-before-deploy:
-    needs: prepare-for-deploy
+    needs: [pr-metadata, prepare-for-deploy]
     runs-on: ubuntu-latest
     timeout-minutes: 1
     concurrency:
-      group: staging_${{ github.event.workflow_run.head_branch }}
+      group: 'staging_${{ needs.pr-metadata.outputs.head_ref }}'
       cancel-in-progress: true
     outputs:
       pull_request_state: ${{ steps.check-pr.outputs.state }}
@@ -313,7 +378,7 @@ jobs:
         id: check-pr
         uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
         env:
-          PR_NUMBER: ${{ env.PR_NUMBER }}
+          PR_NUMBER: ${{ needs.pr-metadata.outputs.number }}
         with:
           script: |
             const { owner, repo } = context.repo
@@ -325,12 +390,12 @@ jobs:
             core.setOutput('state', pullRequest.state)
 
   deploy:
-    needs: [prepare-for-deploy, check-pr-before-deploy]
+    needs: [pr-metadata, prepare-for-deploy, check-pr-before-deploy]
     if: ${{ needs.check-pr-before-deploy.outputs.pull_request_state == 'open' }}
     runs-on: ubuntu-latest
     timeout-minutes: 10
     concurrency:
-      group: staging_${{ github.event.workflow_run.head_branch }}
+      group: 'staging_${{ needs.pr-metadata.outputs.head_ref }}'
       cancel-in-progress: true
     steps:
       - name: Check out repo's default branch
@@ -356,11 +421,11 @@ jobs:
           HEROKU_API_TOKEN: ${{ secrets.HEROKU_API_TOKEN }}
           HYDRO_ENDPOINT: ${{ secrets.HYDRO_ENDPOINT }}
           HYDRO_SECRET: ${{ secrets.HYDRO_SECRET }}
-          PR_URL: ${{ env.PR_URL }}
+          PR_URL: ${{ needs.pr-metadata.outputs.url }}
           SOURCE_BLOB_URL: ${{ needs.prepare-for-deploy.outputs.source_blob_url }}
           CONTEXT_NAME: ${{ env.CONTEXT_NAME }}
           ACTIONS_RUN_LOG: ${{ env.ACTIONS_RUN_LOG }}
-          HEAD_SHA: ${{ env.HEAD_SHA }}
+          HEAD_SHA: ${{ needs.pr-metadata.outputs.head_sha }}
         with:
           script: |
             const { GITHUB_TOKEN, HEROKU_API_TOKEN } = process.env
@@ -462,7 +527,7 @@ jobs:
         env:
           CONTEXT_NAME: ${{ env.CONTEXT_NAME }}
           ACTIONS_RUN_LOG: ${{ env.ACTIONS_RUN_LOG }}
-          HEAD_SHA: ${{ env.HEAD_SHA }}
+          HEAD_SHA: ${{ needs.pr-metadata.outputs.head_sha }}
         with:
           script: |
             const { CONTEXT_NAME, ACTIONS_RUN_LOG, HEAD_SHA } = process.env
@@ -484,4 +549,4 @@ jobs:
           channel: ${{ secrets.DOCS_STAGING_DEPLOYMENT_FAILURES_SLACK_CHANNEL_ID }}
           bot-token: ${{ secrets.SLACK_DOCS_BOT_TOKEN }}
           color: failure
-          text: Staging deployment failed for PR ${{ env.PR_URL }} at commit ${{ github.event.workflow_run.head_sha }}. See ${{ env.ACTIONS_RUN_LOG }}
+          text: Staging deployment failed for PR ${{ needs.pr-metadata.outputs.url }} at commit ${{ needs.pr-metadata.outputs.head_sha }}. See ${{ env.ACTIONS_RUN_LOG }}.
diff --git a/.github/workflows/staging-undeploy-pr.yml b/.github/workflows/staging-undeploy-pr.yml
index c14c18aa72..39d6957628 100644
--- a/.github/workflows/staging-undeploy-pr.yml
+++ b/.github/workflows/staging-undeploy-pr.yml
@@ -14,6 +14,14 @@ permissions:
   deployments: write
 
 jobs:
+  debug:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Dump full context for debugging
+        env:
+          GITHUB_CONTEXT: ${{ toJSON(github) }}
+        run: echo "$GITHUB_CONTEXT"
+
   undeploy:
     if: ${{ github.repository == 'github/docs-internal' || github.repository == 'github/docs' }}
     name: Undeploy