diff --git a/harnesses/terminal-fill-quality/README.md b/harnesses/terminal-fill-quality/README.md
index 648c0f89..1cf18eea 100644
--- a/harnesses/terminal-fill-quality/README.md
+++ b/harnesses/terminal-fill-quality/README.md
@@ -399,6 +399,9 @@ stats plus the last 400 samples (`method_version`, `min_priced`,
 | `RPC_RPS` | `8` | pacing, calls per second |
 | `TICK_SECONDS` | `60` | sweep interval |
 | `DAILY_TARGET` | `400` | swaps read per terminal per day (random draw from the feed) |
+| `SANDWICH` | `1` | `0` turns the sandwich screen off and skips the pool neighbourhood read when the exact mid is known (about a fifth of the Solana reads) |
+| `FAIL_SCAN_BLOCKS` | code defaults | blocks read in full per chain per poll for the EVM fail rate, e.g. `bnb=3,robinhood=0,base=2,ethereum=1` (0 = no fail rate on that chain's event-fed rows; Binance's rows need at least a few, the block sample is their feed) |
+| `NATIVE_POLL_EVERY` | `1` | the EVM log feed polls every N ticks (one `eth_getLogs` per chain per poll) |
 | `EVM_DAILY_TARGET` | `1000` | the same rate for the Relay and native EVM rows (one chain each, so a product's per-chain entry fills at this rate; production runs them at 1,000 so the per-chain windows fill within hours) |
 | `PURGE_EVM_BEFORE` | unset | at load, drop the cross-chain and native EVM rows older than this unix time (once, after a pricing change); the variable stays in the container's env until the next deploy resets it |
 | `PURGE_TERMINALS` | unset | at load, drop every row of these slugs (comma-separated), once, after a feed or attribution change; same caveat |
diff --git a/harnesses/terminal-fill-quality/cmd/script/main.go b/harnesses/terminal-fill-quality/cmd/script/main.go
index 34af51c7..08e1535d 100644
--- a/harnesses/terminal-fill-quality/cmd/script/main.go
+++ b/harnesses/terminal-fill-quality/cmd/script/main.go
@@ -323,6 +323,17 @@ func main() {
 	rpcURL := rpcURLs[0]
 	log.Printf("solana reads: %d endpoint(s), primary %s", len(rpcURLs), redactURL(rpcURL, rpcURL))
 	tick := time.Duration(envInt("TICK_SECONDS", 60)) * time.Second
+	sandwichOn = envInt("SANDWICH", 1) == 1
+	nativePollEvery = max(1, envInt("NATIVE_POLL_EVERY", 1))
+	if v := os.Getenv("FAIL_SCAN_BLOCKS"); v != "" { // e.g. "bnb=3,robinhood=0,base=2,ethereum=1"
+		for _, kv := range strings.Split(v, ",") {
+			if k, n, ok := strings.Cut(strings.TrimSpace(kv), "="); ok {
+				if i, err := strconv.Atoi(strings.TrimSpace(n)); err == nil {
+					failScanBlocks[strings.TrimSpace(k)] = i
+				}
+			}
+		}
+	}
 	dailyTarget := envInt("DAILY_TARGET", 400) // swaps read per terminal per day
 	perTick := float64(dailyTarget) * tick.Seconds() / 86400
 	evmDailyTarget := envInt("EVM_DAILY_TARGET", 1000) // the Relay and native EVM rows: their own rate (one chain each)
@@ -626,6 +637,12 @@ func priceSwap(ctx context.Context, rpc *rpcClient, sw *Swap, tx *parsedTx, pool
 	if sw.PoolVault == "" {
 		return
 	}
+	// The pool neighbourhood costs one signature list plus a transaction
+	// read; with the screen off it is only read when the reference is
+	// still missing (the previous-trade fallback).
+	if !sandwichOn && sw.RefSrc != "" {
+		return
+	}
 	nb, err := poolNeighbours(ctx, rpc, sw)
 	if err != nil {
 		return
@@ -653,6 +670,9 @@ func priceSwap(ctx context.Context, rpc *rpcClient, sw *Swap, tx *parsedTx, pool
 			break
 		}
 	}
+	if !sandwichOn {
+		return
+	}
 	if sd, ok := screenSandwich(ctx, rpc, sw, nb, prevTx, solUSD, now); ok {
 		sw.Scanned = true
 		sw.Sandwich = sd
@@ -660,6 +680,11 @@ func priceSwap(ctx context.Context, rpc *rpcClient, sw *Swap, tx *parsedTx, pool
 	}
 }
 
+// sandwichOn: SANDWICH=0 turns the neighbour screen off (it is not a
+// published column; the reads it costs are about a fifth of the Solana
+// budget). Set at start.
+var sandwichOn = true
+
 // sampleXchain drains the Relay feed: counts every final request of each
 // cross-chain app for its fail rate, draws the tick's quota of successful
 // token settlements on Solana and measures them (see xchain.go).
diff --git a/harnesses/terminal-fill-quality/cmd/script/native.go b/harnesses/terminal-fill-quality/cmd/script/native.go
index 3f96dae3..77ba0f11 100644
--- a/harnesses/terminal-fill-quality/cmd/script/native.go
+++ b/harnesses/terminal-fill-quality/cmd/script/native.go
@@ -421,8 +421,17 @@ func (f *nativeFeed) drain(slug string) (seen int, sample []string, total int) {
 }
 
 // sampleNative draws the tick's quota per native EVM terminal and measures.
+// nativePollEvery: the EVM log feed polls every N ticks (the cursor
+// keeps every block, a poll then covers N minutes of chain); 1 = each tick.
+var nativePollEvery = 1
+var nativeTick int
+
 func sampleNative(ctx context.Context, httpc *http.Client, st *State, nf *nativeFeed, gas map[string]float64, quota map[string]float64, perTick float64) (added, seen int) {
 	nf.funded = st.Funded
+	nativeTick++
+	if nativeTick%nativePollEvery != 0 {
+		return 0, 0
+	}
 	nf.poll(ctx)
 	now := time.Now().Unix()
 	nf.failScan(ctx, st, gas, now)
@@ -431,8 +440,9 @@ func sampleNative(ctx context.Context, httpc *http.Client, st *State, nf *native
 		seen += n0
 		st.record(t.Slug, now, n0, 0, 0, nil)
 		// The quota accrues every tick (a sparse row, one swap a minute,
-		// would otherwise need several active ticks per sample).
-		quota[t.Slug] += perTick
+		// would otherwise need several active ticks per sample); a poll
+		// every N ticks accrues N ticks' worth.
+		quota[t.Slug] += perTick * float64(nativePollEvery)
 		if cap := math.Max(3*perTick, 2); quota[t.Slug] > cap {
 			quota[t.Slug] = cap
 		}