diff --git a/dankclaw/frank-large/quadlet/frank-large.container b/dankclaw/frank-large/quadlet/frank-large.container
index 17ddbfe..199091e 100644
--- a/dankclaw/frank-large/quadlet/frank-large.container
+++ b/dankclaw/frank-large/quadlet/frank-large.container
@@ -100,7 +100,15 @@ Environment=HALOGEN_CTX=262144
 # Doubled 2026-09-12 from the 262144 this had run since 09-11: two full-length
 # conversations resident at once, or four at 131k, instead of one.
 Environment=HALOGEN_KV_POOL_POSITIONS=524288
-Environment=HALOGEN_KV_SLOTS=4
+# Concurrency cap. Each slot is 111.0 MiB of O(1) state; the KV is ONE
+# 524288-position pool carved into per-request regions, so slots cap how many
+# requests run at once while the pool binds how many positions exist. These
+# slots OVERSUBSCRIBE the pool (4 x 262144 > 524288), so admission was always
+# pool-bound -- at most two full-length conversations, or four at 131k.
+# LOWERED 4 -> 3 on 2026-09-12: frees ~111 MiB on a host with 7.1 GiB left,
+# and three users is the real fleet size. A fourth concurrent request now
+# queues behind the three rather than contending.
+Environment=HALOGEN_KV_SLOTS=3
 # Making the doubling stick is budget arithmetic, all of it. ONE budget covers
 # the KV pool, the prefill arena and the vision tower together:
 #