diff --git a/src/frontend/flask_app/templates/measure/select_recipe.html b/src/frontend/flask_app/templates/measure/select_recipe.html
index 98c1ae9..4a04009 100644
--- a/src/frontend/flask_app/templates/measure/select_recipe.html
+++ b/src/frontend/flask_app/templates/measure/select_recipe.html
@@ -13,6 +13,15 @@
        barcodeInput: '',
        barcodeLoading: false,
        barcodeError: '',
+       /* #63/#64: ricetta scelta che richiede lotto/seriale; il pannello compare solo allora. */
+       selected: null,
+       needsTrace(recipe) {
+         return !!(recipe && (recipe.requires_lot || recipe.requires_serial));
+       },
+       choose(recipe) {
+         this.selected = recipe;
+         this.$nextTick(() => { const el = document.getElementById('trace-panel'); if (el) el.scrollIntoView({ behavior: 'smooth', block: 'center' }); });
+       },
        get filteredRecipes() {
          if (!this.search) return this.recipes;
          const q = this.search.toLowerCase();
@@ -62,9 +71,12 @@
              // The scanner is a way in like any other: a recipe that demands a lot
              // demands it here too, or the rule would last exactly as long as it
              // took someone to reach for the barcode reader.
-             const missing = this.missingTraceability(data);
-             if (missing.length) {
-               this.barcodeError = {{ _("Compila prima:")|tojson_attr }} + ' ' + missing.join(', ');
+             // #63/#64: se la ricetta chiede lotto/seriale mancanti, la si sceglie e
+             // compare il pannello con i soli campi richiesti.
+             if (this.missingTraceability(data).length) {
+               this.barcodeModal = false;
+               this.barcodeInput = '';
+               this.choose(data);
                return;
              }
              this.barcodeModal = false;
@@ -149,50 +161,6 @@
     </div>
   </div>
 
-  <!-- Traceability (data entry, NOT a search filter) -->
-  <div class="tmf-card mb-6 border-l-4 border-l-primary">
-    <div class="p-4 sm:p-5">
-      <div class="flex items-center gap-2 mb-3">
-        <svg class="w-5 h-5 text-primary shrink-0" fill="none" stroke="currentColor" stroke-width="1.75" viewBox="0 0 24 24">
-          <path stroke-linecap="round" stroke-linejoin="round" d="M20 7l-8-4-8 4m16 0l-8 4m8-4v10l-8 4m0-10L4 7m8 4v10M4 7v10l8 4"/>
-        </svg>
-        <div>
-          <h2 class="text-sm font-semibold text-[var(--text-primary)] leading-tight">{{ _('Tracciabilità') }}</h2>
-          <p class="text-xs text-[var(--text-muted)] leading-tight">{{ _('Dati del pezzo da misurare — compila prima di selezionare la ricetta') }}</p>
-        </div>
-      </div>
-      <div class="grid grid-cols-1 sm:grid-cols-2 gap-4">
-        <!-- Lot Number -->
-        <div>
-          <label class="tmf-label flex items-center gap-1.5">
-            <svg class="w-3.5 h-3.5 text-amber-500" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
-              <path stroke-linecap="round" stroke-linejoin="round" d="M20 7l-8-4-8 4m16 0l-8 4m8-4v10l-8 4m0-10L4 7m8 4v10M4 7v10l8 4"/>
-            </svg>
-            {{ _('Numero Lotto') }}
-          </label>
-          <input type="text"
-                 x-model="lot_number"
-                 placeholder="{{ _('Es. LOT-2026-001') }}"
-                 class="tmf-input font-mono">
-        </div>
-
-        <!-- Serial Number -->
-        <div>
-          <label class="tmf-label flex items-center gap-1.5">
-            <svg class="w-3.5 h-3.5 text-indigo-500" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
-              <path stroke-linecap="round" stroke-linejoin="round" d="M7 20l4-16m2 16l4-16M6 9h14M4 15h14"/>
-            </svg>
-            {{ _('Numero Seriale') }}
-          </label>
-          <input type="text"
-                 x-model="serial_number"
-                 placeholder="{{ _('Es. SN-000123') }}"
-                 class="tmf-input font-mono">
-        </div>
-      </div>
-    </div>
-  </div>
-
   <!-- Results Count -->
   <div class="flex items-center justify-between mb-4">
     <p class="text-sm text-[var(--text-secondary)]">
@@ -269,30 +237,25 @@
         <div class="px-5 py-3.5 border-t border-[var(--border-color)] bg-[var(--bg-secondary)]
                     rounded-b-xl">
 
-          {# What this recipe insists on before anyone measures. Said on the card
-             rather than after the fact: a measurement taken without its lot cannot
-             be traced back, and finding that out later is finding it out too late. #}
-          <template x-if="missingTraceability(recipe).length">
-            <p class="mb-2 flex items-start gap-1.5 text-xs text-amber-700 dark:text-amber-300">
-              <svg class="w-3.5 h-3.5 shrink-0 mt-px" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
-                <path stroke-linecap="round" stroke-linejoin="round" d="M12 9v3.75m-9.303 3.376c-.866 1.5.217 3.374 1.948 3.374h14.71c1.73 0 2.813-1.874 1.948-3.374L13.949 3.378c-.866-1.5-3.032-1.5-3.898 0L2.697 16.126zM12 15.75h.007v.008H12v-.008z"/>
-              </svg>
-              <span x-text="{{ _('Compila prima:')|tojson_attr }} + ' ' + missingTraceability(recipe).join(', ')"></span>
-            </p>
+          {# #63/#64: una ricetta con lotto/seriale obbligatori si sceglie prima
+             (il pannello compare sotto la griglia); le altre partono subito. #}
+          <template x-if="needsTrace(recipe)">
+            <button type="button" @click="choose(recipe)"
+                    :class="selected && selected.id === recipe.id ? 'ring-2 ring-primary' : ''"
+                    class="btn btn-primary w-full justify-center text-sm font-semibold">
+              {{ _('Seleziona') }}
+            </button>
+          </template>
+          <template x-if="!needsTrace(recipe)">
+            <a :href="buildTaskUrl(recipe.id)"
+               class="btn btn-primary w-full justify-center text-sm font-semibold
+                      transition-shadow duration-200 group-hover:shadow-md">
+              <svg class="w-4 h-4" fill="none" stroke="currentColor" stroke-width="2.5" viewBox="0 0 24 24">
+                <path stroke-linecap="round" stroke-linejoin="round" d="M5 3l14 9-14 9V3z"/>
+              </svg>
+              {{ _('AVVIA ATTIVITÀ') }}
+            </a>
           </template>
-
-          <a :href="missingTraceability(recipe).length ? null : buildTaskUrl(recipe.id)"
-             :aria-disabled="missingTraceability(recipe).length > 0"
-             :class="missingTraceability(recipe).length
-               ? 'opacity-40 cursor-not-allowed pointer-events-none'
-               : 'group-hover:shadow-md'"
-             class="btn btn-primary w-full justify-center text-sm font-semibold
-                    transition-shadow duration-200">
-            <svg class="w-4 h-4" fill="none" stroke="currentColor" stroke-width="2.5" viewBox="0 0 24 24">
-              <path stroke-linecap="round" stroke-linejoin="round" d="M5 3l14 9-14 9V3z"/>
-            </svg>
-            {{ _('AVVIA IN SEQUENZA') }}
-          </a>
 
           {# The whole list, for when the operator wants to see it or go back to a
              task left unfinished. Deliberately the quiet one of the two. #}
@@ -306,6 +269,41 @@
     </template>
   </div>
 
+  <!-- Traceability (#63/#64): compare solo dopo aver scelto una ricetta con
+       requires_lot / requires_serial, con i soli campi richiesti. -->
+  <div id="trace-panel" x-show="selected && needsTrace(selected)" x-cloak
+       class="tmf-card mt-6 border-l-4 border-l-primary">
+    <div class="p-4 sm:p-5">
+      <div class="flex items-center gap-2 mb-3">
+        <svg class="w-5 h-5 text-primary shrink-0" fill="none" stroke="currentColor" stroke-width="1.75" viewBox="0 0 24 24">
+          <path stroke-linecap="round" stroke-linejoin="round" d="M20 7l-8-4-8 4m16 0l-8 4m8-4v10l-8 4m0-10L4 7m8 4v10M4 7v10l8 4"/>
+        </svg>
+        <div>
+          <h2 class="text-sm font-semibold text-[var(--text-primary)] leading-tight">{{ _('Tracciabilità') }}: <span x-text="selected ? selected.name : ''"></span></h2>
+          <p class="text-xs text-[var(--text-muted)] leading-tight">{{ _('Dati del pezzo da misurare — compila prima di selezionare la ricetta') }}</p>
+        </div>
+      </div>
+      <div class="grid grid-cols-1 sm:grid-cols-2 gap-4">
+        <div x-show="selected && selected.requires_lot">
+          <label class="tmf-label">{{ _('Numero Lotto') }}</label>
+          <input type="text" x-model="lot_number"
+                 placeholder="{{ _('Es. LOT-2026-001') }}" class="tmf-input font-mono">
+        </div>
+        <div x-show="selected && selected.requires_serial">
+          <label class="tmf-label">{{ _('Numero Seriale') }}</label>
+          <input type="text" x-model="serial_number"
+                 placeholder="{{ _('Es. SN-000123') }}" class="tmf-input font-mono">
+        </div>
+      </div>
+      <a :href="selected && !missingTraceability(selected).length ? buildTaskUrl(selected.id) : null"
+         :aria-disabled="!selected || missingTraceability(selected).length > 0"
+         :class="(!selected || missingTraceability(selected).length) ? 'opacity-40 cursor-not-allowed pointer-events-none' : ''"
+         class="btn btn-primary w-full justify-center text-sm font-semibold mt-4">
+        {{ _('AVVIA ATTIVITÀ') }}
+      </a>
+    </div>
+  </div>
+
   <!-- Empty State -->
   <div x-show="filteredRecipes.length === 0" x-cloak
        class="text-center py-16">
diff --git a/src/frontend/flask_app/templates/measure/task_execute.html b/src/frontend/flask_app/templates/measure/task_execute.html
index cd925b6..35d0e0c 100644
--- a/src/frontend/flask_app/templates/measure/task_execute.html
+++ b/src/frontend/flask_app/templates/measure/task_execute.html
@@ -115,20 +115,12 @@
           </svg>
           {{ _('Lista task') }}
         </a>
-        <button @click="goToNextTask()"
-                :disabled="!canLeaveTask"
-                :title="canLeaveTask ? '' : blockedReason"
-                :class="canLeaveTask ? '' : 'opacity-40 cursor-not-allowed'"
-                class="btn btn-secondary text-xs py-1 px-2.5 gap-1">
-          <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
-            <path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7"/>
-          </svg>
-          {{ _('Completato') }}
-        </button>
+        {# #60: un solo «Completato», quello grande in fondo (touch); qui resta solo la lista. #}
       </div>
 
       {# Fermo linea + Fine produzione (measurement tasks only) #}
-      <template x-if="isMeasureTask">
+      <template x-if="isMeasureTask && productionRun">
+        {# #61: Fermo linea / Fine produzione solo con una produzione aperta #}
         <div class="shrink-0 flex items-center gap-1.5">
           {# While the line is stopped this becomes the way to restart it, so the
              capoturno never has to hunt for a second control. #}
@@ -756,10 +748,12 @@
         </div>
       </template>
       <template x-if="!isMeasureTask || subtasks.length === 0">
+        {# #60: unico «Completato», largo e alto almeno 64 px per il touch. #}
         <button @click="goToNextTask()"
-                class="btn text-xs shrink-0 gap-1 py-1.5 px-3 shadow-md
+                :disabled="!canLeaveTask"
+                class="btn text-lg font-bold flex-1 w-full min-h-[64px] justify-center gap-2 shadow-md
                        bg-measure-pass text-white hover:opacity-90">
-          <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
+          <svg class="w-5 h-5" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
             <path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7"/>
           </svg>
           {{ _('Completato') }}
@@ -845,6 +839,10 @@
         </div>
       </div>
 
+      {# #61: se il server rifiuta l'avvio produzione, l'errore si vede qui, nell'overlay #}
+      <p x-show="productionError" x-cloak
+         class="mb-2 text-sm text-red-700 dark:text-red-300 text-center" x-text="productionError"></p>
+
       <div class="flex gap-2">
         <button @click="goToSummary()"
                 class="btn btn-secondary flex-1 justify-center gap-2">
@@ -1250,11 +1248,18 @@ function taskExecute() {
     async loadProductionRun() {
       try {
         const resp = await fetch('{{ url_for("measure.api_current_production") }}');
-        if (!resp.ok) return;
+        if (!resp.ok) {
+          // #61: si mostra il detail del server (es. 503 "Stazione non configurata"),
+          // che e' la causa vera; fallback generico se il corpo non e' JSON.
+          const errBody = await resp.json().catch(() => null);
+          this.productionError = (errBody && errBody.detail) || '{{ _("Errore di comunicazione con il server") }}';
+          return;
+        }
         const run = await resp.json();
         if (run && run.id) this.adoptProductionRun(run);
       } catch (e) {
-        // Offline or server down: leave the page usable, just without the timer.
+        // #61: offline o server giu: pagina usabile, ma l'errore e' visibile.
+        this.productionError = '{{ _("Errore di connessione") }}';
       }
     },
 
@@ -1767,13 +1772,9 @@ function taskExecute() {
       this.showCompletionOverlay = false;
       const opened = await this.startProduction();
       if (!opened) {
-        // Server refused: keep the operator working rather than stranding them
-        // mid-shift, but productionError is on screen so it is not silent.
-        this.cycleConfirmed = true;
-        this.cycleCount++;
-        if (this.measurementIntervalMinutes && this.measurementIntervalMinutes > 0) {
-          this.startCountdownFrom(this.measurementIntervalMinutes * 60);
-        }
+        // #61: server rifiuta -> niente timer locale finto; si riapre l'overlay
+        // con l'errore (productionError) cosi' l'operatore puo' riprovare.
+        this.showCompletionOverlay = true;
         return;
       }
       // The START-phase measurements have just been taken: record them as the first
@@ -1821,6 +1822,12 @@ function taskExecute() {
 
     // ---- Open/close supervisor modal (always reset fields) ----
     openSupervisorModal(action) {
+      // #61: fermo/ripresa/fine produzione agiscono su un run: senza run aperto
+      // si dice subito, prima di chiedere le credenziali.
+      if (['fermo_linea', 'ripresa', 'fine_produzione'].includes(action) && !this.productionRun) {
+        this.productionError = '{{ _("Nessuna produzione aperta su questa stazione") }}';
+        return;
+      }
       this.supervisorAction = action;
       this.supervisorUsername = '';
       this.supervisorPassword = '';
diff --git a/src/frontend/flask_app/templates/measure/task_list.html b/src/frontend/flask_app/templates/measure/task_list.html
index e8f841e..e2555cf 100644
--- a/src/frontend/flask_app/templates/measure/task_list.html
+++ b/src/frontend/flask_app/templates/measure/task_list.html
@@ -104,7 +104,7 @@
             <svg class="w-6 h-6" fill="none" stroke="currentColor" stroke-width="2.5" viewBox="0 0 24 24">
               <path stroke-linecap="round" stroke-linejoin="round" d="M5 3l14 9-14 9V3z"/>
             </svg>
-            {{ _('AVVIA IN SEQUENZA') }}
+            {{ _('AVVIA ATTIVITÀ') }}
           </a>
           {% endif %}
           {% endif %}
diff --git a/src/frontend/flask_app/tests/test_operator_flow_ui.py b/src/frontend/flask_app/tests/test_operator_flow_ui.py
index 81f5607..3056bdc 100644
--- a/src/frontend/flask_app/tests/test_operator_flow_ui.py
+++ b/src/frontend/flask_app/tests/test_operator_flow_ui.py
@@ -104,7 +104,7 @@ def test_the_selection_screen_starts_the_sequence(
 def test_avvia_on_the_list_starts_the_sequence(logged_in_client, mock_api_client):
     html = _list_page(logged_in_client, mock_api_client)
     assert "/measure/start/3" in html
-    assert "AVVIA IN SEQUENZA" in html
+    assert "AVVIA ATTIVITÀ" in html
 
 
 # ---------------------------------------------------------------------------
@@ -163,6 +163,32 @@ def test_the_header_offers_completato_not_the_summary(
     assert '@click="goToNextTask()"' in html
 
 
+def test_only_one_completato_and_it_is_big(
+    logged_in_client, mock_api_client, monkeypatch,
+):
+    """#60: «Completato» una sola volta (in basso), largo e alto per il touch."""
+    html = _execute_page(logged_in_client, mock_api_client, monkeypatch)
+    # the label as a button text on its own line (comments in the JS also name it)
+    assert [l.strip() for l in html.splitlines()].count("Completato") == 1
+    assert "min-h-[64px]" in html
+
+
+def test_no_open_run_means_no_fermo_linea_and_no_fake_timer(
+    logged_in_client, mock_api_client, monkeypatch,
+):
+    """#61: senza produzione aperta i pulsanti non si vedono, la modale non si
+    apre e un rifiuto del server non avvia un timer locale finto."""
+    html = _execute_page(logged_in_client, mock_api_client, monkeypatch)
+    assert 'x-if="isMeasureTask && productionRun"' in html
+    assert "!this.productionRun" in html
+    # #61: loadProductionRun mostra il detail del server, non solo il messaggio generico
+    assert "errBody.detail" in html
+    assert "Nessuna produzione aperta su questa stazione" in html
+    # il vecchio ripiego locale non c'e' piu'
+    assert "this.startCountdownFrom(this.measurementIntervalMinutes * 60)" not in html.split(
+        "async startProductionFromOverlay()")[1].split("async confirmCycle")[0]
+
+
 def test_fine_ciclo_is_shown_before_it_can_be_used(
     logged_in_client, mock_api_client, monkeypatch,
 ):
@@ -196,3 +222,27 @@ def test_the_operator_flow_never_links_to_the_statistics(
     ]
     for html in pages:
         assert "/statistics" not in html
+
+
+def test_trace_panel_only_for_recipes_that_require_it(
+    logged_in_client, mock_api_client, monkeypatch,
+):
+    """#63/#64: ricerca+griglia in alto, pannello lotto/seriale solo dopo la
+    scelta di una ricetta che lo richiede, con i soli campi richiesti."""
+    _italian(logged_in_client)
+    monkeypatch.setattr("blueprints.measure.Config.STATION_CODE", "ST-TEST")
+    mock_api_client.get_station_recipes.return_value = [
+        {"id": 1, "code": "A", "name": "Con lotto", "requires_lot": True,
+         "requires_serial": False},
+        {"id": 2, "code": "B", "name": "Libera"},
+    ]
+    html = logged_in_client.get("/measure/select").get_data(as_text=True)
+    assert 'id="trace-panel"' in html
+    assert 'x-show="selected && needsTrace(selected)"' in html
+    assert 'x-show="selected && selected.requires_lot"' in html
+    assert 'x-show="selected && selected.requires_serial"' in html
+    # la ricerca e la griglia precedono il pannello
+    assert html.index("Cerca ricetta") < html.index('id="trace-panel"')
+    assert html.index("Recipe Grid") < html.index('id="trace-panel"')
+    # le ricette senza obblighi partono direttamente
+    assert 'x-if="!needsTrace(recipe)"' in html
diff --git a/src/frontend/flask_app/translations/en/LC_MESSAGES/messages.po b/src/frontend/flask_app/translations/en/LC_MESSAGES/messages.po
index 912994d..cc5fbef 100644
--- a/src/frontend/flask_app/translations/en/LC_MESSAGES/messages.po
+++ b/src/frontend/flask_app/translations/en/LC_MESSAGES/messages.po
@@ -1862,8 +1862,8 @@ msgstr "No description available"
 
 #: templates/measure/select_recipe.html:294
 #: templates/measure/task_list.html:107
-msgid "AVVIA IN SEQUENZA"
-msgstr "START THE SEQUENCE"
+msgid "AVVIA ATTIVITÀ"
+msgstr "START ACTIVITY"
 
 # Maker - Task Editor
 #: templates/measure/select_recipe.html:302
diff --git a/src/frontend/flask_app/translations/it/LC_MESSAGES/messages.po b/src/frontend/flask_app/translations/it/LC_MESSAGES/messages.po
index 8106e84..20f4cc8 100644
--- a/src/frontend/flask_app/translations/it/LC_MESSAGES/messages.po
+++ b/src/frontend/flask_app/translations/it/LC_MESSAGES/messages.po
@@ -1864,8 +1864,8 @@ msgstr "Nessuna descrizione disponibile"
 
 #: templates/measure/select_recipe.html:294
 #: templates/measure/task_list.html:107
-msgid "AVVIA IN SEQUENZA"
-msgstr "AVVIA IN SEQUENZA"
+msgid "AVVIA ATTIVITÀ"
+msgstr "AVVIA ATTIVITÀ"
 
 # Maker - Task Editor
 #: templates/measure/select_recipe.html:302
diff --git a/src/frontend/flask_app/translations/messages.pot b/src/frontend/flask_app/translations/messages.pot
index d3ffafc..439b499 100644
--- a/src/frontend/flask_app/translations/messages.pot
+++ b/src/frontend/flask_app/translations/messages.pot
@@ -1825,7 +1825,7 @@ msgstr ""
 
 #: templates/measure/select_recipe.html:294
 #: templates/measure/task_list.html:107
-msgid "AVVIA IN SEQUENZA"
+msgid "AVVIA ATTIVITÀ"
 msgstr ""
 
 #: templates/measure/select_recipe.html:302