diff --git a/.github/scripts/monitor_slurm_job.sh b/.github/scripts/monitor_slurm_job.sh
index cb69e5c01..3d4c4a717 100755
--- a/.github/scripts/monitor_slurm_job.sh
+++ b/.github/scripts/monitor_slurm_job.sh
@@ -86,7 +86,15 @@ is_terminal_state() {
 # (Phoenix 'embers') a job can stay PENDING for hours, burning the CI job
 # timeout and holding a runner slot; fail early so it reads as queue starvation,
 # not a test failure. 0 = wait indefinitely.
-: "${SLURM_MAX_QUEUE_SECONDS:=5400}"   # 90 minutes
+#
+# The budget has to clear a normal bad day on a busy machine, or it converts
+# routine queue pressure into red CI. Frontier's own numbers make the case:
+# over one week, MFC jobs on `batch` waited p50=1m but p90=96m and p95=176m,
+# with a 466m tail. A 90-minute budget cut into that distribution, tripping on
+# 11% of the jobs that did eventually start -- plus the ones that never did.
+# Four hours clears p95 with room to spare while staying well inside the 480m
+# job-level `timeout-minutes`, which remains the real backstop.
+: "${SLURM_MAX_QUEUE_SECONDS:=14400}"   # 4 hours
 # Reject a non-integer override rather than silently skipping the budget.
 if ! [[ "$SLURM_MAX_QUEUE_SECONDS" =~ ^[0-9]+$ ]]; then
   echo "ERROR: SLURM_MAX_QUEUE_SECONDS must be a non-negative integer (seconds), got '$SLURM_MAX_QUEUE_SECONDS'" >&2
diff --git a/.github/scripts/submit-slurm-job.sh b/.github/scripts/submit-slurm-job.sh
index 6803b3766..16035419b 100755
--- a/.github/scripts/submit-slurm-job.sh
+++ b/.github/scripts/submit-slurm-job.sh
@@ -62,7 +62,10 @@ case "$cluster" in
         # CFD154; submitting under it now fails outright with "Invalid qos
         # specification". "normal" is the only QOS on this allocation without a
         # one-job-at-a-time cap, so it is the only one that can run the CI
-        # matrix concurrently.
+        # matrix concurrently. Note that the g1 partition carries its own
+        # partition QOS (also named "g1"), which slurmctld applies on its own
+        # when a job lands there. Do not add --qos=g1: CFD154 has no
+        # association with it and sbatch rejects the job outright.
         qos="normal"
         # Let each job's slurmstepd broker its own steps instead of routing
         # every srun through slurmctld. The in-job test suite launches ~1700+
@@ -105,9 +108,11 @@ if [ "$device" = "cpu" ]; then
 #SBATCH --mem-per-cpu=8G"
             ;;
         frontier|frontier_amd)
+            # g1 is a dedicated 64-node carve-out; its nodes are not in batch,
+            # so CI starts promptly instead of queueing behind the machine.
             sbatch_device_opts="\
 #SBATCH -n 32
-#SBATCH -p batch"
+#SBATCH -p g1"
             ;;
     esac
 elif [ "$device" = "gpu" ]; then
@@ -135,7 +140,7 @@ elif [ "$device" = "gpu" ]; then
         frontier|frontier_amd)
             sbatch_device_opts="\
 #SBATCH -n 8
-#SBATCH -p batch"
+#SBATCH -p g1"
             ;;
     esac
 else