diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 407ad68..295df10 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -184,8 +184,19 @@ jobs:
   # Beside the build rather than behind it: it signs nothing and uploads nothing,
   # it just drives simulators, and it takes about as long. On a dry run too -
   # the artifact is the only way to look at the pictures before the store does.
+  # A runner per device rather than one doing both. Two simulators on the seven
+  # gigabytes a runner has spent their time swapping, and the runs took five
+  # times as long as they do alone; a device to a machine is that, structurally.
+  # It halves the wall clock as well, since the two halves photograph at once.
   screenshots:
     runs-on: macos-26
+    # long by nature, but the default is six hours for a wedged simulator to sit in
+    timeout-minutes: 180
+    strategy:
+      # one device failing should not throw away the other's hour of work
+      fail-fast: false
+      matrix:
+        device: [iphone, ipad]
     steps:
       - name: checkout
         uses: actions/checkout@v7
@@ -205,16 +216,28 @@ jobs:
           python-version: "3.13"
       - run: python3 -m pip install --quiet Pillow
 
-      # the lane checks the set it produced, so a language that came out short
-      # fails here rather than half way up to App Store Connect
-      - name: photograph both devices in every locale
+      # The lane builds once into build/screenshots and photographs eighteen
+      # times without building again. Keeping it means a rerun starts at the
+      # first simulator instead of at the compiler. Keyed on everything the
+      # build reads, so a stale one is never used - only ever missed.
+      - name: reuse the last build
+        uses: actions/cache@v4
+        with:
+          path: build/screenshots
+          key: screenshots-${{ matrix.device }}-${{ runner.os }}-${{ env.xcode_version }}-${{ hashFiles('OpenDocumentReader.xcodeproj/project.pbxproj', 'OpenDocumentReader.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved', 'OpenDocumentReader/**', 'OpenDocumentReaderUITests/**', 'Ads/**', 'NoAds/**', 'configs/**', 'scripts/make-screenshot-documents.py') }}
+
+      # half a set, so the lane does not check it - the job below does, once
+      # both halves are in
+      - name: photograph the ${{ matrix.device }} in every locale
+        env:
+          ODR_SCREENSHOT_DEVICE: ${{ matrix.device }}
         run: bundle exec fastlane ios screenshots
 
       # what the store is given
       - name: archive the framed screenshots
         uses: actions/upload-artifact@v7
         with:
-          name: framed
+          name: framed-${{ matrix.device }}
           path: fastlane/framed
           if-no-files-found: error
           # png, so there is nothing left to squeeze out of them
@@ -223,20 +246,72 @@ jobs:
       # and what they were framed from, which is where to look when a picture
       # comes out wrong
       - name: archive the raw captures
+        # also when the lane failed: a half finished set is what says which
+        # language it got to
+        if: ${{ !cancelled() }}
         uses: actions/upload-artifact@v7
         with:
-          name: screenshots
+          name: screenshots-${{ matrix.device }}
           path: fastlane/screenshots
-          if-no-files-found: error
+          if-no-files-found: warn
           compression-level: 0
 
       - uses: actions/upload-artifact@v7
         if: failure()
         with:
-          name: screenshot-log
+          name: screenshot-log-${{ matrix.device }}
           path: ~/Library/Logs/snapshot
           if-no-files-found: warn
 
+  # The two halves put back together, and only now checked: a set is both
+  # devices in every locale, and neither runner above can see the other's.
+  # Republished under the names the release reads.
+  screenshot-set:
+    needs: screenshots
+    runs-on: ubuntu-24.04
+    steps:
+      - name: checkout
+        uses: actions/checkout@v7
+
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.13"
+
+      - name: fetch both halves
+        uses: actions/download-artifact@v8
+        with:
+          pattern: framed-*
+          merge-multiple: true
+          path: fastlane/framed
+
+      - name: fetch what they were framed from
+        uses: actions/download-artifact@v8
+        with:
+          pattern: screenshots-*
+          merge-multiple: true
+          path: fastlane/screenshots
+
+      # the check the lane cannot do on half a set: every locale, both devices,
+      # at a size App Store Connect takes
+      - name: check the set
+        run: scripts/store_screenshots.py --screenshots fastlane/framed
+
+      - name: archive the framed screenshots
+        uses: actions/upload-artifact@v7
+        with:
+          name: framed
+          path: fastlane/framed
+          if-no-files-found: error
+          compression-level: 0
+
+      - name: archive the raw captures
+        uses: actions/upload-artifact@v7
+        with:
+          name: screenshots
+          path: fastlane/screenshots
+          if-no-files-found: warn
+          compression-level: 0
+
   # a job per app, fail-fast off, so "Re-run failed jobs" can retry one half
   upload:
     needs: build
@@ -275,7 +350,7 @@ jobs:
   # while a build cannot be uploaded twice. No macOS runner: this touches the
   # listing, not the app
   listing:
-    needs: [upload, screenshots]
+    needs: [upload, screenshot-set]
     if: ${{ !inputs.dry_run }}
     runs-on: ubuntu-24.04
     strategy:
diff --git a/OpenDocumentReaderUITests/ScreenshotTests.swift b/OpenDocumentReaderUITests/ScreenshotTests.swift
index 969be0b..c464d63 100644
--- a/OpenDocumentReaderUITests/ScreenshotTests.swift
+++ b/OpenDocumentReaderUITests/ScreenshotTests.swift
@@ -19,6 +19,10 @@ final class ScreenshotTests: XCTestCase {
 
     override func setUpWithError() throws {
         continueAfterFailure = false
+
+        // A ceiling, not a target: six launches on a shared runner outrun
+        // XCTest's ten minute default and get killed mid-test.
+        executionTimeAllowance = 1800
     }
 
     @MainActor
@@ -125,7 +129,10 @@ final class ScreenshotTests: XCTestCase {
     private func dismissTheKeyboardTutorial(in app: XCUIApplication) {
         let continueButton = app.buttons["Continue"]
 
-        if continueButton.waitForExistence(timeout: 2) {
+        // Short, because this waits its whole timeout on every run that does not
+        // need it - which is all of them while the launch argument holds. The
+        // panel comes up with the keyboard, and the keyboard is already up here.
+        if continueButton.waitForExistence(timeout: 0.5) {
             continueButton.tap()
         }
     }
diff --git a/fastlane/Fastfile b/fastlane/Fastfile
index 3728204..6b2d763 100644
--- a/fastlane/Fastfile
+++ b/fastlane/Fastfile
@@ -30,14 +30,19 @@ MAKE_DOCUMENTS = File.expand_path("../scripts/make-screenshot-documents.py").fre
 SCREENSHOT_DIR = File.expand_path("screenshots").freeze
 FRAMED_DIR = File.expand_path("framed").freeze
 
+# Named, where snapshot would pick a fresh temp directory each run. The app is
+# built once into it and then photographed eighteen times without building
+# again, and CI keeps it between runs.
+SCREENSHOT_BUILD_DIR = File.expand_path("../build/screenshots").freeze
+
 # The two sizes App Store Connect asks an app that runs on both for, named by
 # whatever the runner's Xcode calls them. Newest first, and the first one the
 # runner actually has wins - a simulator's name changes with every Xcode, the
 # number of pixels it has does not, and store_screenshots.py checks that.
-SCREENSHOT_DEVICES = [
-  ["iPhone 17 Pro Max", "iPhone 16 Pro Max", "iPhone 15 Pro Max"],
-  ["iPad Pro 13-inch (M5)", "iPad Pro 13-inch (M4)", "iPad Pro (12.9-inch) (6th generation)"],
-].freeze
+SCREENSHOT_DEVICES = {
+  "iphone" => ["iPhone 17 Pro Max", "iPhone 16 Pro Max", "iPhone 15 Pro Max"],
+  "ipad" => ["iPad Pro 13-inch (M5)", "iPad Pro 13-inch (M4)", "iPad Pro (12.9-inch) (6th generation)"],
+}.freeze
 
 def dry_run?
   ENV["ODR_DRY_RUN"].to_s.strip == "true"
@@ -94,7 +99,8 @@ def screenshot_devices(ios)
 
   available = simulators_by_ios.fetch(ios, [])
 
-  SCREENSHOT_DEVICES.map do |candidates|
+  screenshot_kinds.map do |kind|
+    candidates = SCREENSHOT_DEVICES.fetch(kind)
     candidates.find { |name| available.include?(name) } ||
       UI.user_error!(
         "none of #{candidates.join(', ')} runs iOS #{ios}. That runtime has: " \
@@ -104,6 +110,19 @@ def screenshot_devices(ios)
   end
 end
 
+# Which of the two the run is for. Both unless one is named, so a run started by
+# hand is the whole set - only the release splits them, a device to a runner.
+def screenshot_kinds
+  given = ENV["ODR_SCREENSHOT_DEVICE"].to_s.strip.downcase
+  return SCREENSHOT_DEVICES.keys if given.empty?
+
+  unless SCREENSHOT_DEVICES.key?(given)
+    UI.user_error!("no such device: #{given}. One of #{SCREENSHOT_DEVICES.keys.join(', ')}.")
+  end
+
+  [given]
+end
+
 platform :ios do
   desc "Build a signed .ipa of the paid app"
   lane :buildPro do
@@ -149,6 +168,20 @@ platform :ios do
     # it starts - a file written later lands in the next build, not this one.
     sh(MAKE_DOCUMENTS)
 
+    # Built once, here. snapshot asks xcodebuild to build and then test on every
+    # run, and there are eighteen of them - two devices in nine languages. The
+    # build is the same every time, and checking it is still up to date costs
+    # about two minutes on a runner.
+    scan(
+      project: "OpenDocumentReader.xcodeproj",
+      scheme: "ODR Screenshots",
+      # not a device: this is the one build both simulators are photographed from
+      destination: "generic/platform=iOS Simulator",
+      derived_data_path: SCREENSHOT_BUILD_DIR,
+      build_for_testing: true,
+      skip_detect_devices: true
+    )
+
     # The Pro scheme, so no ad sdk is linked and no consent form can come up in
     # front of a picture. The two apps are the same app, and what differs - the
     # banner Lite carries - is not in a screenshot either way, so one set of
@@ -178,7 +211,18 @@ platform :ios do
       skip_helper_version_check: true,
       # the runner has no browser to open the summary in, and no one watching it
       skip_open_summary: true,
-      stop_after_first_error: true
+      stop_after_first_error: true,
+      # one device per xcodebuild rather than both at once: two simulators
+      # rendering on a three core runner took ten minutes over one, and ran the
+      # test out of the time XCTest allows it
+      concurrent_simulators: false,
+      # the build above, photographed as it stands
+      derived_data_path: SCREENSHOT_BUILD_DIR,
+      test_without_building: true,
+      # the language the app is given is not the language the status bar is
+      # drawn in, and an iPad's status bar carries the date. Without this it
+      # reads Mon Aug 17 over a Russian document.
+      localize_simulator: true
     )
 
     # A raw capture is not what the store shows. The framing is separate from the
@@ -189,12 +233,16 @@ platform :ios do
 
     # what came out is what the store would be given, so it is checked here
     # rather than at upload time on the other side of the run. A run narrowed to
-    # a few languages by hand has nothing to check against: half a set is what it
-    # was asked for.
-    if ENV["ODR_SCREENSHOT_LANGUAGES"].to_s.strip.empty?
-      sh(STORE_SCREENSHOTS, "--screenshots", FRAMED_DIR)
+    # some of the languages or to one of the devices has nothing to check
+    # against: half a set is what it was asked for, and the release checks the
+    # two halves together once both runners have handed theirs in.
+    narrowed = %w[ODR_SCREENSHOT_LANGUAGES ODR_SCREENSHOT_DEVICE ODR_SCREENSHOT_DEVICES]
+      .any? { |name| !ENV[name].to_s.strip.empty? }
+
+    if narrowed
+      UI.important("#{devices.join(', ')} in #{languages.join(', ')} is not a full set, so it is not checked")
     else
-      UI.important("only #{languages.join(', ')} were captured, so the set is not checked")
+      sh(STORE_SCREENSHOTS, "--screenshots", FRAMED_DIR)
     end
   end