diff --git a/cohere_vector/index-vectors-only-mapping.json b/cohere_vector/index-vectors-only-mapping.json
index bfdd00250..b8e586582 100644
--- a/cohere_vector/index-vectors-only-mapping.json
+++ b/cohere_vector/index-vectors-only-mapping.json
@@ -4,17 +4,13 @@
       {% if preload_pagecache %}
     "index.store.preload": [ "vec", "vex", "vem"],
       {% endif %}
+    "index.mapping.source.mode": "synthetic",
     "index.number_of_shards": {{number_of_shards | default(1)}},
     "index.number_of_replicas": {{number_of_replicas | default(0)}}
     {%- endif -%}{# non-serverless-index-settings-marker-end #}
   },
   "mappings": {
     "dynamic": false,
-    {%- if build_flavor != "serverless" -%}
-    "_source": {
-      "mode": "synthetic"
-    },
-    {%- endif -%}
     "properties": {
       "emb": {
         "type": "dense_vector",
diff --git a/elastic/logs/templates/component/track-shared-logsdb-mode.json b/elastic/logs/templates/component/track-shared-logsdb-mode.json
index 7831005d7..41326b5d1 100644
--- a/elastic/logs/templates/component/track-shared-logsdb-mode.json
+++ b/elastic/logs/templates/component/track-shared-logsdb-mode.json
@@ -4,6 +4,9 @@
         {% if index_mode %}
         "index": {
             "mode": {{ index_mode | tojson }}
+            {% if source_mode %}
+            ,"mapping.source.mode": {{ source_mode | tojson }}
+            {% endif %}
             {% if use_synthetic_source_recovery %}
             ,"recovery.use_synthetic_source": {{use_synthetic_source_recovery | tojson}}
             {% endif %}
@@ -12,13 +15,6 @@
             {% endif %}
         }
         {% endif %}
-      },
-      "mappings": {
-        {% if source_mode %}
-        "_source": {
-          "mode": {{ source_mode | tojson }}
-        }
-        {% endif %}
       }
     }
   }
diff --git a/elastic/security/templates/component/track-shared-logsdb-mode.json b/elastic/security/templates/component/track-shared-logsdb-mode.json
index fc644f403..1b590707f 100644
--- a/elastic/security/templates/component/track-shared-logsdb-mode.json
+++ b/elastic/security/templates/component/track-shared-logsdb-mode.json
@@ -4,6 +4,9 @@
         {% if index_mode %}
         "index": {
             "mode": {{ index_mode | tojson }},
+            {% if source_mode %}
+            "mapping.source.mode": {{ source_mode | tojson }},
+            {% endif %}
             {% if use_synthetic_source_recovery %}
             "recovery.use_synthetic_source": {{use_synthetic_source_recovery | tojson}},
             {% endif %}
@@ -15,13 +18,6 @@
             "sort.missing": ["_first", "_last"]
         }
         {% endif %}
-      },
-      "mappings": {
-        {% if source_mode %}
-        "_source": {
-          "mode": {{ source_mode | tojson }}
-        }
-        {% endif %}
       }
     }
   }
diff --git a/http_logs/index.json b/http_logs/index.json
index 1e696e5a9..513041867 100644
--- a/http_logs/index.json
+++ b/http_logs/index.json
@@ -13,6 +13,9 @@
     "index.sort.field": ["@timestamp"],
     "index.sort.order":["desc"]
     {%- endif %}
+    {% if source_mode %}
+    ,"mapping.source.mode": {{ source_mode | tojson }}
+    {% endif %}
   },
   "mappings": {
     "dynamic": "strict",
@@ -20,9 +23,6 @@
     {%- else %}
     "_source": {
       "enabled": {{ source_enabled | default(true) | tojson }}
-      {% if source_mode %}
-      "mode": {{ source_mode | tojson }},
-      {% endif %}
     },
     {%- endif %}
     "properties": {
diff --git a/k8s_metrics/templates/metrics-kubernetes.pod@custom.json b/k8s_metrics/templates/metrics-kubernetes.pod@custom.json
index 6ac8d40be..8acd860a0 100644
--- a/k8s_metrics/templates/metrics-kubernetes.pod@custom.json
+++ b/k8s_metrics/templates/metrics-kubernetes.pod@custom.json
@@ -14,6 +14,7 @@
           {%- endif %}
           "codec": "best_compression",
           "mapping": {
+            "source.mode": "synthetic",
             "total_fields": {
               "limit": "10000"
             }
@@ -70,9 +71,6 @@
         }
       },
       "mappings": {
-        "_source": {
-          "mode": "synthetic"
-        },
         "dynamic_templates": [
           {
             "container.labels": {
diff --git a/k8s_metrics/templates/metrics-kubernetes.pod@package.json b/k8s_metrics/templates/metrics-kubernetes.pod@package.json
index b87bbb1a0..e3e4cd780 100644
--- a/k8s_metrics/templates/metrics-kubernetes.pod@package.json
+++ b/k8s_metrics/templates/metrics-kubernetes.pod@package.json
@@ -7,6 +7,7 @@
         "index": {
           "codec": "best_compression",
           "mapping": {
+            "source.mode": "synthetic",
             "total_fields": {
               "limit": "10000"
             }
@@ -63,9 +64,6 @@
         }
       },
       "mappings": {
-        "_source": {
-          "mode": "synthetic"
-        },
         "dynamic_templates": [
           {
             "container.labels": {
diff --git a/msmarco-v2-vector/index-vectors-only-mapping.json b/msmarco-v2-vector/index-vectors-only-mapping.json
index de5227bab..735f6f18c 100644
--- a/msmarco-v2-vector/index-vectors-only-mapping.json
+++ b/msmarco-v2-vector/index-vectors-only-mapping.json
@@ -8,6 +8,7 @@
       {% if preload_pagecache %}
       "store.preload": [ "vec", "vex", "vem"],
       {% endif %}
+      "mapping.source.mode": "synthetic",
       "number_of_shards": {{number_of_shards | default(1)}},
       "number_of_replicas": {{number_of_replicas | default(0)}}
       {% if aggressive_merge_policy %},
@@ -24,9 +25,6 @@
   },
   "mappings": {
     "dynamic": false,
-    "_source": {
-      "mode": "synthetic"
-    },
     "properties": {
       "docid": {
         "type": "keyword"
diff --git a/nyc_taxis/index.json b/nyc_taxis/index.json
index 00910de6f..13705f63e 100644
--- a/nyc_taxis/index.json
+++ b/nyc_taxis/index.json
@@ -7,14 +7,11 @@
     "index.number_of_shards": {{number_of_shards | default(1)}},
     "index.number_of_replicas": {{number_of_replicas | default(0)}},
       {% endif %}
-    "index.requests.cache.enable": false
+    "index.requests.cache.enable": false,
+    "index.mapping.source.mode": {{ source_mode | default("stored") | tojson }}
     {%- endif -%}{# non-serverless-index-settings-marker-end #}
   },
   "mappings": {
-    "_source": {
-      "mode": {{ source_mode | default("stored") | tojson }}
-
-    },
     "properties": {
       "surcharge": {
         "scaling_factor": 100,
diff --git a/random_vector/index-mapping.json b/random_vector/index-mapping.json
index 316ff7e07..2dcbf5fb7 100644
--- a/random_vector/index-mapping.json
+++ b/random_vector/index-mapping.json
@@ -7,16 +7,14 @@
       {%- endif -%}{# non-serverless-index-settings-marker-end #}
       "sort": {
         "field": "partition_id"
-      }
+      },
+      "mapping.source.mode": "synthetic"
     }
   },
   "mappings": {
     "_routing": {
       "required": true
     },
-    "_source": {
-      "mode": "synthetic"
-    },
     "properties": {
       "partition_id": {
         "type": "keyword"
diff --git a/tsdb/index-template.json b/tsdb/index-template.json
index 37d76a1e8..de1c85a4b 100644
--- a/tsdb/index-template.json
+++ b/tsdb/index-template.json
@@ -8,6 +8,7 @@
     "settings": {
       "index": {
         {# non-serverless-index-settings-marker-start #}{%- if build_flavor != "serverless" or serverless_operator == true -%}
+        "mapping.source.mode": {{ p_source_mode | tojson }},
         "number_of_shards": {{number_of_shards | default(1)}},
         "number_of_replicas": {{number_of_replicas | default(0)}},
         "requests.cache.enable": false,
@@ -44,9 +45,6 @@
         "beat": "metricbeat",
         "version": "7.6.2"
       },
-      "_source": {
-        "mode": {{ p_source_mode | tojson }}
-      },
       "dynamic_templates": [
         {
           "labels": {
diff --git a/tsdb/index.json b/tsdb/index.json
index d5fe6feae..940047bbc 100644
--- a/tsdb/index.json
+++ b/tsdb/index.json
@@ -5,6 +5,7 @@
   "settings": {
     "index": {
       {# non-serverless-index-settings-marker-start #}{%- if build_flavor != "serverless" or serverless_operator == true -%}
+      "mapping.source.mode": {{ p_source_mode | tojson }},
       "number_of_shards": {{number_of_shards | default(1)}},
       "number_of_replicas": {{number_of_replicas | default(0)}},
       "requests.cache.enable": false,
@@ -44,9 +45,6 @@
       "beat": "metricbeat",
       "version": "7.6.2"
     },
-    "_source": {
-      "mode": {{ p_source_mode | tojson }}
-    },
     "dynamic_templates": [
       {
         "labels": {