diff --git a/connito/shared/config.py b/connito/shared/config.py
index 8d05fb7..55d27c2 100644
--- a/connito/shared/config.py
+++ b/connito/shared/config.py
@@ -484,7 +484,7 @@ class TaskCfg(BaseConfig):
     _LOCKED_FIELDS: ClassVar[frozenset[str]] = frozenset({
         "expert_group_name", "helper_group_id", "routing_mode",
     })
-    expert_group_name: str = "exp_math"
+    expert_group_name: str = "exp_metamath_p02"
     load_all_expert_groups: bool = False
     base_path: Path = Path("expert_groups")
     path: Path | None = None
diff --git a/expert_groups/exp_metamath_p02/config.yaml b/expert_groups/exp_metamath_p02/config.yaml
index 14ddeef..bd07692 100644
--- a/expert_groups/exp_metamath_p02/config.yaml
+++ b/expert_groups/exp_metamath_p02/config.yaml
@@ -1,4 +1,4 @@
-group_id: -1  # sentinel: not assigned to a functioning slot (would clash with exp_math=0 if left at the default)
+group_id: 3  # active trainable slot for the MetaMathQA expert group (distinct from exp_math=0, helper exp_c4_p02=2)
 # MetaMathQA-SFT ESFT-Token @ p=0.2
 # Auto-generated from ESFT-Token @ p=0.2 profiling.
 # Total experts across 26 MoE layers: 146