diff --git a/scripts/serve-frank-large.sh b/scripts/serve-frank-large.sh
index e803b31..9819078 100755
--- a/scripts/serve-frank-large.sh
+++ b/scripts/serve-frank-large.sh
@@ -88,7 +88,16 @@ export LD_LIBRARY_PATH="$(dirname "$LLAMA_BIN"):${ROCM_LIB}/lib:${ROCM_CORE}/lib
 export HIP_VISIBLE_DEVICES=0
 export HSA_OVERRIDE_GFX_VERSION=11.5.1
 export GGML_CUDA_GRAPH_OPT=0
-export LLAMA_TARGET_GREEDY_ARGMAX_FASTPATH=1
+# The pinned runner sets the target exact-Q8 greedy argmax fast path
+# (LLAMA_TARGET_GREEDY_ARGMAX_FASTPATH=1). That fast path fails closed on
+# any non-greedy request (temperature != 0, top_k > 1, top_p < 1, penalties,
+# grammar, logit bias, or reasoning budget). The model card's own chat
+# instructions override sampling per request with Qwen live values (temp
+# 0.7, top-p 0.8, top-k 20, min-p 0, presence_penalty 1.5), which the fast
+# path rejects. Production chat therefore forces it to 0. This does NOT
+# affect the Kairic Edge IU4 lane (prompt/verification route via
+# --kairic-edge) nor the MTP draft fast path below.
+export LLAMA_TARGET_GREEDY_ARGMAX_FASTPATH=0
 export LLAMA_MTP_CPU_ARGMAX_FASTPATH=1
 export PROMPTFORGE_TARGET_ONLY=0
 export PROMPTFORGE_MODE=iu4_ffn