diff --git a/scripts/hyde/elmhurst_lib.py b/scripts/hyde/elmhurst_lib.py
index 4f137988..9b27443d 100644
--- a/scripts/hyde/elmhurst_lib.py
+++ b/scripts/hyde/elmhurst_lib.py
@@ -64,8 +64,12 @@ HERE = Path(__file__).parent
 SESSION_DIR = HERE / ".elmhurst-session"
 CREDS_FILE = HERE / ".elmhurst-creds.json"  # gitignored; {"access":..,"pwd":..}
 
-# The single reusable campaign assessment ("Khalim-test"). Overwrite it per UPRN.
-ASSESSMENT_GUID = "B44A0DB4-4C08-4241-B818-86F060172105"
+# The reusable campaign assessment ("Khalim-test"), overwritten per UPRN. Can be
+# overridden per run via the `ELM_GUID` env var (e.g. a per-UPRN assessment under
+# a different account) — see Limitations "parameterize the GUID".
+ASSESSMENT_GUID = os.environ.get(
+    "ELM_GUID", "B44A0DB4-4C08-4241-B818-86F060172105"
+)
 ENTRY_URL = (
     "https://rdsap10online.elmhurstenergy.co.uk/Processing/WebFormAddress.aspx"
     f"?Guid={ASSESSMENT_GUID}"
@@ -98,17 +102,31 @@ def session() -> Generator[tuple[BrowserContext, Page], None, None]:
             headless=False,
             accept_downloads=True,
             viewport={"width": 1400, "height": 1000},
+            # Container /dev/shm is tiny (64M) → chromium renderer "Target
+            # crashed" mid-build without this. --no-sandbox for rootless Xvfb.
+            args=["--disable-dev-shm-usage", "--no-sandbox"],
         )
         page = ctx.pages[0] if ctx.pages else ctx.new_page()
         page.on("dialog", lambda d: d.accept())
-        page.goto(ENTRY_URL, wait_until="networkidle", timeout=60_000)
-        if "WebFormLogin" in page.url:
-            access, pwd = _creds()
-            page.fill("#ctl00_ctl00_ContentBody_ContentBody_TextBoxAccessCode", access)
-            page.fill("#ctl00_ctl00_ContentBody_ContentBody_TextBoxPassword", pwd)
-            with page.expect_navigation(wait_until="networkidle", timeout=60_000):
-                page.click("#ctl00_ctl00_ContentBody_ContentBody_ImageButtonEnter")
-            page.wait_for_timeout(1000)
+        # Login can be slow/flaky; retry the whole goto+fill a few times.
+        for attempt in range(4):
+            try:
+                page.goto(ENTRY_URL, wait_until="domcontentloaded", timeout=60_000)
+                if "WebFormLogin" not in page.url:
+                    break  # already authed (server session still valid)
+                access, pwd = _creds()
+                ac = "#ctl00_ctl00_ContentBody_ContentBody_TextBoxAccessCode"
+                page.wait_for_selector(ac, state="visible", timeout=30_000)
+                page.fill(ac, access)
+                page.fill("#ctl00_ctl00_ContentBody_ContentBody_TextBoxPassword", pwd)
+                with page.expect_navigation(wait_until="networkidle", timeout=60_000):
+                    page.click("#ctl00_ctl00_ContentBody_ContentBody_ImageButtonEnter")
+                page.wait_for_timeout(1000)
+                if "WebFormLogin" not in page.url:
+                    break
+            except PlaywrightTimeoutError:
+                print(f"  login attempt {attempt+1} timed out, retrying...", flush=True)
+                page.wait_for_timeout(2000)
         try:
             yield ctx, page
         finally: