diff --git a/backend/src/api/websocket-handler.ts b/backend/src/api/websocket-handler.ts
index b082573f1..34d4682d2 100644
--- a/backend/src/api/websocket-handler.ts
+++ b/backend/src/api/websocket-handler.ts
@@ -282,8 +282,7 @@ class WebsocketHandler {
           }
 
           if (Object.keys(response).length) {
-            const serializedResponse = this.serializeResponse(response);
-            client.send(serializedResponse);
+            client.send(this.serializeResponse(response));
           }
         } catch (e) {
           logger.debug(`Error parsing websocket message from ${client['remoteAddress']}: ` + (e instanceof Error ? e.message : e));
@@ -392,8 +391,7 @@ class WebsocketHandler {
       }
 
       if (Object.keys(response).length) {
-        const serializedResponse = this.serializeResponse(response);
-        client.send(serializedResponse);
+        client.send(this.serializeResponse(response));
       }
     });
   }
@@ -639,8 +637,7 @@ class WebsocketHandler {
       }
 
       if (Object.keys(response).length) {
-        const serializedResponse = this.serializeResponse(response);
-        client.send(serializedResponse);
+        client.send(this.serializeResponse(response));
       }
     });
   }
@@ -738,10 +735,13 @@ class WebsocketHandler {
       }
     }
 
+    const confirmedTxids: { [txid: string]: boolean } = {};
+
     // Update mempool to remove transactions included in the new block
     for (const txId of txIds) {
       delete _memPool[txId];
       rbfCache.mined(txId);
+      confirmedTxids[txId] = true;
     }
 
     if (config.MEMPOOL.ADVANCED_GBT_MEMPOOL) {
@@ -773,6 +773,8 @@ class WebsocketHandler {
       'fees': fees,
     });
 
+    const mBlocksWithTransactions = mempoolBlocks.getMempoolBlocksWithTransactions();
+
     const responseCache = { ...this.socketData };
     function getCachedResponse(key, data): string {
       if (!responseCache[key]) {
@@ -808,7 +810,7 @@ class WebsocketHandler {
 
       if (client['track-tx']) {
         const trackTxid = client['track-tx'];
-        if (trackTxid && txIds.indexOf(trackTxid) > -1) {
+        if (trackTxid && confirmedTxids[trackTxid]) {
           response['txConfirmed'] = JSON.stringify(trackTxid);
         } else {
           const mempoolTx = _memPool[trackTxid];
@@ -880,17 +882,24 @@ class WebsocketHandler {
 
       if (client['track-mempool-block'] >= 0 && memPool.isInSync()) {
         const index = client['track-mempool-block'];
-        if (mBlockDeltas && mBlockDeltas[index]) {
-          response['projected-block-transactions'] = getCachedResponse(`projected-block-transactions-${index}`, {
-            index: index,
-            delta: mBlockDeltas[index],
-          });
+
+        if (mBlockDeltas && mBlockDeltas[index] && mBlocksWithTransactions[index]?.transactions?.length) {
+          if (mBlockDeltas[index].added.length > (mBlocksWithTransactions[index]?.transactions.length / 2)) {
+            response['projected-block-transactions'] = getCachedResponse(`projected-block-transactions-full-${index}`, {
+              index: index,
+              blockTransactions: mBlocksWithTransactions[index].transactions,
+            });
+          } else {
+            response['projected-block-transactions'] = getCachedResponse(`projected-block-transactions-delta-${index}`, {
+              index: index,
+              delta: mBlockDeltas[index],
+            });
+          }
         }
       }
 
       if (Object.keys(response).length) {
-        const serializedResponse = this.serializeResponse(response);
-        client.send(serializedResponse);
+        client.send(this.serializeResponse(response));
       }
     });
   }
@@ -951,10 +960,27 @@ class WebsocketHandler {
 
   private printLogs(): void {
     if (this.wss) {
+      let numTxSubs = 0;
+      let numProjectedSubs = 0;
+      let numRbfSubs = 0;
+
+      this.wss.clients.forEach((client) => {
+        if (client['track-tx']) {
+          numTxSubs++;
+        }
+        if (client['track-mempool-block'] >= 0) {
+          numProjectedSubs++;
+        }
+        if (client['track-rbf']) {
+          numRbfSubs++;
+        }
+      })
+
       const count = this.wss?.clients?.size || 0;
       const diff = count - this.numClients;
       this.numClients = count;
       logger.debug(`${count} websocket clients | ${this.numConnected} connected | ${this.numDisconnected} disconnected | (${diff >= 0 ? '+' : ''}${diff})`);
+      logger.debug(`websocket subscriptions: track-tx: ${numTxSubs}, track-mempool-block: ${numProjectedSubs} track-rbf: ${numRbfSubs}`);
       this.numConnected = 0;
       this.numDisconnected = 0;
     }
diff --git a/frontend/src/app/components/mempool-block-overview/mempool-block-overview.component.ts b/frontend/src/app/components/mempool-block-overview/mempool-block-overview.component.ts
index 4beda043a..f09b8f5ea 100644
--- a/frontend/src/app/components/mempool-block-overview/mempool-block-overview.component.ts
+++ b/frontend/src/app/components/mempool-block-overview/mempool-block-overview.component.ts
@@ -35,6 +35,8 @@ export class MempoolBlockOverviewComponent implements OnInit, OnDestroy, OnChang
   blockSub: Subscription;
   deltaSub: Subscription;
 
+  firstLoad: boolean = true;
+
   constructor(
     public stateService: StateService,
     private websocketService: WebsocketService,
@@ -58,7 +60,40 @@ export class MempoolBlockOverviewComponent implements OnInit, OnDestroy, OnChang
       )
       .pipe(switchMap(() => this.stateService.mempoolBlockTransactions$))
       .subscribe((transactionsStripped) => {
-        this.replaceBlock(transactionsStripped);
+        if (this.firstLoad) {
+          this.replaceBlock(transactionsStripped);
+        } else {
+          const inOldBlock = {};
+          const inNewBlock = {};
+          const added: TransactionStripped[] = [];
+          const changed: { txid: string, rate: number | undefined, acc: boolean | undefined }[] = [];
+          const removed: string[] = [];
+          for (const tx of transactionsStripped) {
+            inNewBlock[tx.txid] = true;
+          }
+          for (const txid of Object.keys(this.blockGraph?.scene?.txs || {})) {
+            inOldBlock[txid] = true;
+            if (!inNewBlock[txid]) {
+              removed.push(txid);
+            }
+          }
+          for (const tx of transactionsStripped) {
+            if (!inOldBlock[tx.txid]) {
+              added.push(tx);
+            } else {
+              changed.push({
+                txid: tx.txid,
+                rate: tx.rate,
+                acc: tx.acc
+              });
+            }
+          }
+          this.updateBlock({
+            removed,
+            changed,
+            added
+          });
+        }
       });
     this.deltaSub = this.stateService.mempoolBlockDelta$.subscribe((delta) => {
       this.updateBlock(delta);
@@ -67,6 +102,7 @@ export class MempoolBlockOverviewComponent implements OnInit, OnDestroy, OnChang
 
   ngOnChanges(changes): void {
     if (changes.index) {
+      this.firstLoad = true;
       if (this.blockGraph) {
         this.blockGraph.clear(changes.index.currentValue > changes.index.previousValue ? this.chainDirection : this.poolDirection);
       }