diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3607eb6..8ddb292 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [1.4.3] - 20260910
+### Changed
+- Update default values.yaml to improve performance when openning big files and reduce .jupyter_ystore.db size.
+
 ## [1.4.2] - 20260504
 ### Changed
 - Update version of Jupyter Hub dependency to 4.3.4
diff --git a/charts/helix/Chart.yaml b/charts/helix/Chart.yaml
index ad00e78..7cc3bdd 100644
--- a/charts/helix/Chart.yaml
+++ b/charts/helix/Chart.yaml
@@ -20,7 +20,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: "1.4.2"
+version: "1.4.3"
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
diff --git a/charts/helix/configuration/jupyterhub/07-kubespawner_singleuser_pod_manifest_configuration.py b/charts/helix/configuration/jupyterhub/07-kubespawner_singleuser_pod_manifest_configuration.py
index b6b985b..c465a4f 100644
--- a/charts/helix/configuration/jupyterhub/07-kubespawner_singleuser_pod_manifest_configuration.py
+++ b/charts/helix/configuration/jupyterhub/07-kubespawner_singleuser_pod_manifest_configuration.py
@@ -158,6 +158,17 @@ def set_mounted_pvc_names_as_env_vars(spawner, pod):
         set_pvc_env_vars(notebook_container, pvc_volumes)
         set_mount_path_env_vars(notebook_container, mounted_volumes_with_paths)
 
+def set_customs_env_vars(spawner, pod):
+    notebook_container = get_notebook_container(pod.spec.containers)
+    try :
+        for name, value in notebook_container.extra_env.items():
+            if name == "PYDEVD_DISABLE_FILE_VALIDATION":
+                continue
+
+            add_env_vars(notebook_container, name, value)
+    except Exception as e:
+        spawner.log.error("ERROR\nImpossible to add some var env: %s", e)
+
 
 def modify_pod_hook(spawner, pod):
     """Modifie le manifeste du pod singleuser pour inclure dans le conteneur notebook le nom des PVCs monté en variable d'envirronement."""
@@ -167,6 +178,7 @@ def modify_pod_hook(spawner, pod):
         spawner.log.info(
         f"Injecting PVC names bounded to user {spawner.user.name} as environment variables")
         set_mounted_pvc_names_as_env_vars(spawner, pod)
+        set_customs_env_vars(spawner, pod)
 
 
     except Exception as e:
diff --git a/charts/helix/tests/values.yaml b/charts/helix/tests/values.yaml
index 5dcc706..f16e1c1 100644
--- a/charts/helix/tests/values.yaml
+++ b/charts/helix/tests/values.yaml
@@ -294,6 +294,16 @@ jupyterhub:
 
     extraEnv:
       PYDEVD_DISABLE_FILE_VALIDATION: "1"
+      DISK_THRESHOLD : "3"
+
+    extraFiles:
+      collaboration-config:
+        mountPath: /etc/jupyter/jupyter_server_config.json
+        data:
+          SQLiteYStore:
+            squash_after_inactivity_of: 3600
+          YDocExtension:
+            document_load_progressively: true
 
     # This section configures KubeSpawner directly to some extent but also indirectly through 
     # Helm chart specific configuration options such as singleuser.storage.type.
diff --git a/charts/helix/values.yaml b/charts/helix/values.yaml
index a90d2c7..d728b48 100644
--- a/charts/helix/values.yaml
+++ b/charts/helix/values.yaml
@@ -321,6 +321,17 @@ jupyterhub:
 
     extraEnv:
       PYDEVD_DISABLE_FILE_VALIDATION: "1"
+      DISK_THRESHOLD: "70" # Percentage of usage before displaying a terminal notification
+
+    # Add extra configuration in your Jupyterlab
+    extraFiles:
+      collaboration-config:
+        mountPath: /etc/jupyter/jupyter_server_config.json
+        data:
+          SQLiteYStore:
+            squash_after_inactivity_of: 3600
+          YDocExtension:
+            document_load_progressively: true
 
     # This section configures KubeSpawner directly to some extent but also indirectly through 
     # Helm chart specific configuration options such as singleuser.storage.type.