diff --git a/plugins/platforms/matrix/adapter.py b/plugins/platforms/matrix/adapter.py
index 3835d8e31efa6..f32dc18725212 100644
--- a/plugins/platforms/matrix/adapter.py
+++ b/plugins/platforms/matrix/adapter.py
@@ -131,6 +131,7 @@ class _TrustStateStub:  # type: ignore[no-redef]
     _ssrf_redirect_guard,
 )
 from gateway.platforms.helpers import ThreadParticipationTracker
+from utils import env_float
 
 logger = logging.getLogger(__name__)
 
@@ -946,11 +947,13 @@ def __init__(self, config: PlatformConfig):
 
         # Text batching: merge rapid successive messages (Telegram-style).
         # Matrix clients split long messages around 4000 chars.
-        self._text_batch_delay_seconds = float(
-            os.getenv("HERMES_MATRIX_TEXT_BATCH_DELAY_SECONDS", "0.6")
-        )
-        self._text_batch_split_delay_seconds = float(
-            os.getenv("HERMES_MATRIX_TEXT_BATCH_SPLIT_DELAY_SECONDS", "2.0")
+        # env_float tolerates a malformed value (e.g. a "0.6s" unit-suffix typo)
+        # instead of raising ValueError out of __init__ and crashing gateway
+        # boot — matching how the sibling adapters (Feishu/WeCom/Discord/Telegram)
+        # read this same HERMES_<PLATFORM>_TEXT_BATCH_* family.
+        self._text_batch_delay_seconds = env_float("HERMES_MATRIX_TEXT_BATCH_DELAY_SECONDS", 0.6)
+        self._text_batch_split_delay_seconds = env_float(
+            "HERMES_MATRIX_TEXT_BATCH_SPLIT_DELAY_SECONDS", 2.0
         )
         self._pending_text_batches: Dict[str, MessageEvent] = {}
         self._pending_text_batch_tasks: Dict[str, asyncio.Task] = {}
diff --git a/plugins/platforms/simplex/adapter.py b/plugins/platforms/simplex/adapter.py
index ae4c6be34b64d..3c9f3c6713b32 100644
--- a/plugins/platforms/simplex/adapter.py
+++ b/plugins/platforms/simplex/adapter.py
@@ -66,6 +66,7 @@
     MessageType,
     SendResult,
 )
+from utils import env_float
 
 logger = logging.getLogger(__name__)
 
@@ -191,9 +192,9 @@ def __init__(self, config: PlatformConfig, **kwargs):
 
         # Text message batching — concatenate rapid-fire messages into one
         # event before dispatching, mirroring Telegram's batching.
-        self._text_batch_delay = float(
-            os.getenv("HERMES_SIMPLEX_TEXT_BATCH_DELAY", "0.8")
-        )
+        # env_float tolerates a malformed value instead of raising out of
+        # __init__ (mirrors the other text-batch adapters).
+        self._text_batch_delay = env_float("HERMES_SIMPLEX_TEXT_BATCH_DELAY", 0.8)
         self._pending_text_batches: Dict[str, MessageEvent] = {}
         self._pending_text_batch_tasks: Dict[str, asyncio.Task] = {}
 
diff --git a/tests/gateway/test_matrix.py b/tests/gateway/test_matrix.py
index d239728b79419..46ae2c17c5b01 100644
--- a/tests/gateway/test_matrix.py
+++ b/tests/gateway/test_matrix.py
@@ -5309,3 +5309,37 @@ async def _ok():
 
         assert ran["ok"] is True  # the sibling handler still ran
         assert "event handler failed" in caplog.text  # failure surfaced, not swallowed
+class TestMatrixTextBatchEnvParsing:
+    """A malformed HERMES_MATRIX_TEXT_BATCH_* value must not crash adapter init.
+
+    The env-cast sweep (a7dd98c86) routed these casts through utils.env_float for
+    Feishu/WeCom/Discord/Telegram but missed Matrix. A non-numeric value (e.g. a
+    ``0.6s`` unit-suffix typo) previously raised ValueError out of __init__,
+    which propagates through the gateway platform-init loop and aborts boot.
+    """
+
+    def _build(self):
+        from plugins.platforms.matrix.adapter import MatrixAdapter
+
+        return MatrixAdapter(
+            PlatformConfig(
+                enabled=True,
+                token="tok",
+                extra={"homeserver": "https://matrix.example.org"},
+            )
+        )
+
+    def test_malformed_delay_falls_back_to_default(self, monkeypatch):
+        monkeypatch.setenv("HERMES_MATRIX_TEXT_BATCH_DELAY_SECONDS", "0.6s")
+        adapter = self._build()  # must not raise ValueError
+        assert adapter._text_batch_delay_seconds == 0.6
+
+    def test_malformed_split_delay_falls_back_to_default(self, monkeypatch):
+        monkeypatch.setenv("HERMES_MATRIX_TEXT_BATCH_SPLIT_DELAY_SECONDS", "abc")
+        adapter = self._build()  # must not raise ValueError
+        assert adapter._text_batch_split_delay_seconds == 2.0
+
+    def test_valid_delay_is_honored(self, monkeypatch):
+        monkeypatch.setenv("HERMES_MATRIX_TEXT_BATCH_DELAY_SECONDS", "1.5")
+        adapter = self._build()
+        assert adapter._text_batch_delay_seconds == 1.5