diff --git a/experiments/cross-chain-bridge/localnet/app-rewards-harness.mjs b/experiments/cross-chain-bridge/localnet/app-rewards-harness.mjs
index 9ab3d7e..11244e3 100644
--- a/experiments/cross-chain-bridge/localnet/app-rewards-harness.mjs
+++ b/experiments/cross-chain-bridge/localnet/app-rewards-harness.mjs
@@ -61,13 +61,25 @@ const EVIDENCE_FILE = process.env.OZ_EVIDENCE_FILE ?? null
 const REWARD_TIMEOUT_MS = Number(process.env.OZ_REWARD_TIMEOUT_S ?? 900) * 1000
 const TRAFFIC_TIMEOUT_MS = Number(process.env.OZ_TRAFFIC_TIMEOUT_S ?? 300) * 1000
 const POLL_INTERVAL_MS = 5000
+// Scan ingests a transaction from the SV participant after the submitting
+// participant has committed it. This bounds the wait for that ingestion.
+const SCAN_TIMEOUT_MS = 120 * 1000
 
 const LEDGER_TOKEN = process.env.OZ_LEDGER_TOKEN_FILE
   ? readFileSync(process.env.OZ_LEDGER_TOKEN_FILE, 'utf8').trim()
   : null
 
+// Templates of Splice's `splice-amulet` Daml package, addressed by package
+// name (`#<package-name>:<module>:<template>`) so that the Ledger API resolves
+// them across every version of the package instead of one pinned package id.
+// Each link shows the definition at Splice 0.8.3, the LocalNet release that
+// `scripts/ledger.sh` defaults to.
+// https://github.com/canton-network/splice/blob/8460154135f39019b8bb370c9c1321ff13c9bb10/daml/splice-amulet/daml/Splice/AmuletRules.daml#L172
 const AMULET_RULES = '#splice-amulet:Splice.AmuletRules:AmuletRules'
+// https://github.com/canton-network/splice/blob/8460154135f39019b8bb370c9c1321ff13c9bb10/daml/splice-amulet/daml/Splice/Amulet.daml#L447
 const REWARD_COUPON_V2 = '#splice-amulet:Splice.Amulet:RewardCouponV2'
+// https://github.com/canton-network/splice/blob/8460154135f39019b8bb370c9c1321ff13c9bb10/daml/splice-amulet/daml/Splice/Amulet.daml#L303
+const FEATURED_APP_RIGHT = '#splice-amulet:Splice.Amulet:FeaturedAppRight'
 
 // The parties of the Daml Script record `BridgeParties`, in its field names.
 const ROLES = ['ba', 'br', 'pa', 'wtokAdmin', 'recipient', 'holder', 'attester1', 'attester2', 'attester3']
@@ -207,7 +219,10 @@ const latestRound = async () => Number((await scanApi('GET', '/v0/dso')).latest_
 
 // Feature `party` with the DevNet choice. A fresh validator buys its first
 // synchronizer traffic on its own interval, so the first submission that costs
-// traffic may be refused until then; the loop retries.
+// traffic may be refused until then; the loop retries. The submit returns once
+// the participant holds the right, so its ACS confirms the right at once. Scan
+// ingests the right from the SV participant later, so the check on Scan polls
+// for the contract.
 async function featureParty(role, party) {
   const dso = await scanApi('GET', '/v0/dso')
   const rules = dso.amulet_rules.contract
@@ -228,9 +243,13 @@ async function featureParty(role, party) {
       throw err
     }
   }, TRAFFIC_TIMEOUT_MS)
-  const featured = await scanApi('GET', '/v0/featured-apps')
-  const mine = (featured.featured_apps ?? []).filter((a) => a.payload?.provider === party)
-  if (mine.length !== 1) fail(`Scan reports ${mine.length} featured app rights for ${role}, expected 1`)
+  const rights = await acs(party, FEATURED_APP_RIGHT)
+  if (rights.length !== 1) fail(`the participant holds ${rights.length} featured app rights for ${role}, expected 1`)
+  const { contractId } = rights[0]
+  await waitFor(`Scan to list the featured app right of ${role}`, async () => {
+    const featured = await scanApi('GET', '/v0/featured-apps')
+    return (featured.featured_apps ?? []).some((a) => a.contract_id === contractId) ? contractId : null
+  }, SCAN_TIMEOUT_MS)
   log(`featured ${role} (${party.slice(0, 24)}...)`)
 }
 
diff --git a/experiments/interoperability/traffic-rewards/harness.mjs b/experiments/interoperability/traffic-rewards/harness.mjs
index 7655a64..06a4d68 100644
--- a/experiments/interoperability/traffic-rewards/harness.mjs
+++ b/experiments/interoperability/traffic-rewards/harness.mjs
@@ -65,6 +65,9 @@ const REWARD_TIMEOUT_MS = Number(process.env.OZ_REWARD_TIMEOUT_S ?? 900) * 1000
 // A fresh app-provider validator holds no synchronizer traffic. It buys traffic
 // from the SV on its own interval, so the first call that costs traffic waits.
 const TRAFFIC_TIMEOUT_MS = Number(process.env.OZ_TRAFFIC_TIMEOUT_S ?? 300) * 1000
+// Scan ingests a transaction from the SV participant after the submitting
+// participant has committed it. This bounds the wait for that ingestion.
+const SCAN_TIMEOUT_MS = 120 * 1000
 const POLL_INTERVAL_MS = 5000
 
 // The token of the participant admin user. The gate mints it, because the same
@@ -83,9 +86,12 @@ const T = {
   // Splice packages, which LocalNet vets on the app-provider participant. The
   // `#package-name` form resolves to the highest vetted version, so the pin is
   // `OZ_SPLICE_VERSION` of `scripts/ledger.sh`. This client reads the payloads of
-  // Splice 0.7.1, and a release that changes either one fails an assertion below
-  // rather than reporting a version mismatch here.
+  // Splice 0.8.3, and a release that changes either one fails an assertion below
+  // rather than reporting a version mismatch here. Each link shows the
+  // definition at Splice 0.8.3.
+  // https://github.com/canton-network/splice/blob/8460154135f39019b8bb370c9c1321ff13c9bb10/daml/splice-amulet/daml/Splice/Amulet.daml#L447
   rewardCouponV2: '#splice-amulet:Splice.Amulet:RewardCouponV2',
+  // https://github.com/canton-network/splice/blob/8460154135f39019b8bb370c9c1321ff13c9bb10/daml/splice-api-reward-assignment-v1/daml/Splice/Api/RewardAssignmentV1.daml#L40
   rewardCoupon: '#splice-api-reward-assignment-v1:Splice.Api.RewardAssignmentV1:RewardCoupon',
 }
 
@@ -447,6 +453,7 @@ async function selfFeature() {
     },
     TRAFFIC_TIMEOUT_MS,
   )
+  let contractId = null
   if (!status.has_featured_app_right) {
     // A fresh validator holds no synchronizer traffic and buys it from the SV on
     // its own interval, and it answers 429 until then.
@@ -462,12 +469,25 @@ async function selfFeature() {
       },
       TRAFFIC_TIMEOUT_MS,
     )
-    log(`self-granted the featured app right (${granted.contract_id.slice(0, 16)}...)`)
+    contractId = granted.contract_id
+    log(`self-granted the featured app right (${contractId.slice(0, 16)}...)`)
   } else {
     log('the app-provider already holds a featured app right')
   }
-  const featured = await scanApi('GET', '/v0/featured-apps')
-  const mine = (featured.featured_apps ?? []).filter((a) => a.payload?.provider === status.party_id)
+  // The wallet answers once the validator has committed the right, and Scan
+  // ingests it from the SV participant later, so the check on Scan polls. A
+  // right granted here matches on its contract id; a right from an earlier run
+  // matches on the provider.
+  const matches = (a) => (contractId ? a.contract_id === contractId : a.payload?.provider === status.party_id)
+  const mine = await waitFor(
+    'Scan to list the featured app right of the app-provider',
+    async () => {
+      const featured = await scanApi('GET', '/v0/featured-apps')
+      const hits = (featured.featured_apps ?? []).filter(matches)
+      return hits.length > 0 ? hits : null
+    },
+    SCAN_TIMEOUT_MS,
+  )
   assertEq('Scan reports one featured app right for the app-provider', mine.length, 1)
   return status.party_id
 }
diff --git a/scripts/ledger.sh b/scripts/ledger.sh
index 94a956a..0f352ea 100644
--- a/scripts/ledger.sh
+++ b/scripts/ledger.sh
@@ -141,7 +141,7 @@ ledger_init() {
 	LEDGER_JSON_API_URL="${OZ_JSON_API_URL:-http://127.0.0.1:$LEDGER_JSON_API_PORT}"
 
 	LOCALNET_KEEP="${OZ_KEEP_LOCALNET:-0}"
-	LOCALNET_SPLICE_VERSION="${OZ_SPLICE_VERSION:-0.7.1}"
+	LOCALNET_SPLICE_VERSION="${OZ_SPLICE_VERSION:-0.8.3}"
 	LOCALNET_SPLICE_REPO="${OZ_SPLICE_REPO:-https://github.com/canton-network/splice.git}"
 	LOCALNET_PROJECT="${OZ_LOCALNET_PROJECT:-oz-localnet-gate}"
 	LOCALNET_PARTY_HINT="${OZ_LOCALNET_PARTY_HINT:-ozspecs-interop-1}"