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@@ -6,6 +6,54 @@ _rotOnly/head-bone normalize/upgradeStreetPeople). Measurements on the M3 Ultra
 
 ---
 
+## ROUND 28 — v5.1 THE SWEEP: instrument LOD — **KILLED with the measurement** (ledger #4)
+
+*PROCITY-D, 2026-07-17. The oldest tri item on the books (v3.1-era). The brief attached the wind-sway rule:
+**"if the measured win is <20k tris in practice, KILL the item with the measurement and it leaves the
+backlog forever."** It does not survive. **E: do not build the `_lo` variants — that work is now unnecessary.***
+
+### The measurement
+Instrument tri counts, parsed straight from the shipped depot GLBs (`web/assets/models/`):
+
+| instrument | tris |
+|---|---|
+| electric_guitar | 14,000 |
+| bass_guitar | 14,000 |
+| drum_kit | 14,000 |
+| guitar_amp | 14,000 |
+| mic_stand | 14,000 |
+| **band + amp, all on stage** | **70,000** |
+
+On paper that clears the bar: a 3–4k `_lo` each would "save" ~52k. **But the rule says *in practice*, and the
+brief named the reason — "interiors are close-quarters."** So I measured the rooms an LOD would have to fire in
+(live, all three venue archetypes, `interiorMode` driven by hand since rAF is throttled):
+
+| venue | room | **max diagonal** | room tris (no band) | draws |
+|---|---|---|---|---|
+| pub — The Exchange Hotel | 9.7 × 9.7 m | 13.7 m | 12,522 | 38 |
+| band_room — The Vinyl Shed | 8.9 × 9.6 m | 13.0 m | 11,699 | 35 |
+| rsl — Wangaratta RSL (biggest) | 12 × 9.4 m | **15.2 m** | 15,115 | 38 |
+
+### The verdict: practical win = **0 tris**. KILLED.
+**A player can never be more than 15.2 m from the band** — that is corner-to-corner in the *largest* venue, and
+the stage sits at one end, so the real stage-to-player max is shorter still. An LOD is a *distance* trade: it
+pays when the subject is small on screen. Inside a ≤15.2 m room the band is never small — it is the subject of
+the gig, and of F's tour money shot. Any sane swap threshold (15–25 m) **never fires**; an aggressive 8 m one
+would fire only in half a room, at a distance where a 3–4 k `_lo` is *visibly* worse with no perceptual cover.
+The win is not "small" — it is **structurally zero**, because the distance the LOD needs does not exist in this
+game. **Per the wind-sway rule: killed, off the backlog forever.**
+
+No budget motivates it either: a venue interior is ~12–15 k tris, ~85 k with the band — comfortably inside the
+200 k stress ceiling E's R22 tri diet restored, at 35–38 draws against a ≤350 ceiling.
+
+### Side-observation for E (NOT a proposal — no breach motivates it)
+All five instruments are **exactly 14,000 tris**, which is a decimator target, not a measurement of the objects:
+a **mic stand does not need 14 k**. If instrument tris ever *do* become the driver of a real breach, the lever is
+a **flat re-decimation by object complexity** (mic stand → ~1 k), which beats any LOD because it needs no
+distance — not a `_lo` swap. Filing the observation so the next tri hunt starts from it; **not** asking for work.
+
+---
+
 ## ROUND 23 — v5.0-alpha: the GIG_RANGE chunk-neighbour fix (ledger #6, the carried v4.x item)
 
 *PROCITY-D, 2026-07-16. My own filed finding, finally fixed — post-release, as Fable scheduled. Hot path,