diff --git a/neptune-core/src/application/loops/main_loop/proof_upgrader.rs b/neptune-core/src/application/loops/main_loop/proof_upgrader.rs
index 333498e84..fdf11e138 100644
--- a/neptune-core/src/application/loops/main_loop/proof_upgrader.rs
+++ b/neptune-core/src/application/loops/main_loop/proof_upgrader.rs
@@ -255,7 +255,17 @@ impl UpgradeJob {
             TxProvingCapability::PrimitiveWitness => {
                 panic!("Client cannot have primitive witness capability only")
             }
-            TxProvingCapability::LockScript => todo!("TODO: Add support for this"),
+            TxProvingCapability::LockScript if network.use_mock_proof() => {
+                UpgradeJob::PrimitiveWitnessToSingleProof(PrimitiveWitnessToSingleProof {
+                    primitive_witness,
+                })
+            }
+            TxProvingCapability::LockScript => {
+                panic!(
+                    "Client cannot upgrade primitive witness with lock-script-only proving capability; use \
+                     --tx-proving-capability=proofcollection or singleproof to broadcast transactions"
+                )
+            }
         }
     }
 
diff --git a/neptune-core/src/application/loops/sync_loop/synchronization_bit_mask.rs b/neptune-core/src/application/loops/sync_loop/synchronization_bit_mask.rs
index 651333f0e..5c78528ef 100644
--- a/neptune-core/src/application/loops/sync_loop/synchronization_bit_mask.rs
+++ b/neptune-core/src/application/loops/sync_loop/synchronization_bit_mask.rs
@@ -149,10 +149,31 @@ impl SynchronizationBitMask {
     /// put it into canonical representation. Canonical representation means
     /// the `lower_bound` field points to the first zero.
     fn canonize(mut self) -> SynchronizationBitMask {
-        // TODO: very slow. improve perf!
-        while self.contains(self.lower_bound) {
-            self.lower_bound += 1;
-            if self.lower_bound.is_multiple_of(32) {
+        while self.lower_bound < self.upper_bound && self.contains(self.lower_bound) {
+            if self.limbs.is_empty() {
+                break;
+            }
+            let rel = (self.lower_bound % 32) as u32;
+            let first = self.limbs[0];
+            let max_bits_in_limb = u64::from(32 - rel);
+            let remaining = self.upper_bound - self.lower_bound;
+            let chunk = max_bits_in_limb.min(remaining);
+            let chunk_u32 = u32::try_from(chunk).expect("chunk fits in u32");
+            let mask = if chunk_u32 == 32 {
+                u32::MAX
+            } else {
+                (1u32 << chunk_u32) - 1
+            };
+            let shifted = first >> rel;
+            let run = u64::from((shifted & mask).trailing_ones());
+            if run == 0 {
+                break;
+            }
+            let advance = run.min(remaining);
+            let old_lb = self.lower_bound;
+            self.lower_bound += advance;
+            let boundaries_crossed = (self.lower_bound / 32).saturating_sub(old_lb / 32);
+            for _ in 0..boundaries_crossed {
                 self.limbs.pop_front();
             }
         }
diff --git a/neptune-core/src/state/transaction/tx_proving_capability.rs b/neptune-core/src/state/transaction/tx_proving_capability.rs
index b32863be1..328b0349b 100644
--- a/neptune-core/src/state/transaction/tx_proving_capability.rs
+++ b/neptune-core/src/state/transaction/tx_proving_capability.rs
@@ -28,7 +28,9 @@ impl From<TxProvingCapability> for TransactionProofType {
     fn from(c: TxProvingCapability) -> Self {
         match c {
             TxProvingCapability::PrimitiveWitness => Self::PrimitiveWitness,
-            TxProvingCapability::LockScript => unimplemented!(),
+            // No distinct proof type: lock-script capability proves the same
+            // on-chain primitive-witness shape; prover jobs still use PW type.
+            TxProvingCapability::LockScript => Self::PrimitiveWitness,
             TxProvingCapability::ProofCollection => Self::ProofCollection,
             TxProvingCapability::SingleProof => Self::SingleProof,
         }
@@ -93,6 +95,15 @@ impl rand::distr::Distribution<TxProvingCapability> for rand::distr::StandardUni
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::protocol::consensus::transaction::transaction_proof::TransactionProofType;
+
+    #[test]
+    fn lockscript_maps_to_primitive_witness_proof_type() {
+        assert_eq!(
+            TransactionProofType::PrimitiveWitness,
+            TxProvingCapability::LockScript.into()
+        );
+    }
 
     #[test]
     fn can_prove_simple() {