diff --git a/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ContainerUploaderBase.kt b/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ContainerUploaderBase.kt
index e673ea11..c7536f76 100644
--- a/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ContainerUploaderBase.kt
+++ b/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ContainerUploaderBase.kt
@@ -276,8 +276,9 @@ abstract class ContainerUploaderBase(
         effectiveCompressionType: CompressionType = local.compressionType,
     ): BlobSource {
         // Select container using incrementing counter for round-robin distribution
+        // Note: Math.floorMod handles negative values correctly if overflow occurs
         var containerIndex =
-            containerIndexCounter.getAndIncrement() % containers.size
+            Math.floorMod(containerIndexCounter.getAndIncrement(), containers.size)
 
         logger.debug(
             "Starting upload with {} containers, round-robin index: {}",
@@ -389,9 +390,9 @@ abstract class ContainerUploaderBase(
         )
         // TODO check and validate failure scenarios
         // Use semaphore for true streaming parallelism
-        // This allows up to maxConcurrency concurrent uploads, starting new ones as soon as slots
+        // This allows up to effectiveMaxConcurrency concurrent uploads, starting new ones as soon as slots
         // are available
-        val semaphore = Semaphore(maxConcurrency)
+        val semaphore = Semaphore(effectiveMaxConcurrency)
 
         // Launch all uploads concurrently, but semaphore limits actual concurrent execution
         val results =
diff --git a/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ICustomUploader.kt b/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ICustomUploader.kt
index f2bd6bc9..ea82e90f 100644
--- a/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ICustomUploader.kt
+++ b/ingest-v2/src/main/kotlin/com/microsoft/azure/kusto/ingest/v2/uploader/ICustomUploader.kt
@@ -45,13 +45,6 @@ interface ICustomUploader : Closeable {
     ): CompletableFuture<UploadResults>
 }
 
-/**
- * Extension function to convert [ICustomUploader] to [IUploader].
- *
- * Kotlin users can use this as: `myCustomUploader.asUploader()`
- */
-fun ICustomUploader.asUploader(): IUploader = CustomUploaderAdapter(this)
-
 /**
  * Static helper methods for [ICustomUploader].
  *
diff --git a/quickstart/src/main/java/com/microsoft/azure/kusto/quickstart/SampleApp.java b/quickstart/src/main/java/com/microsoft/azure/kusto/quickstart/SampleApp.java
index 8dd33075..1d4f81c0 100644
--- a/quickstart/src/main/java/com/microsoft/azure/kusto/quickstart/SampleApp.java
+++ b/quickstart/src/main/java/com/microsoft/azure/kusto/quickstart/SampleApp.java
@@ -1,9 +1,8 @@
 package com.microsoft.azure.kusto.quickstart;
 
 import com.azure.core.tracing.opentelemetry.OpenTelemetryTracer;
+import com.azure.core.credential.TokenCredential;
 import com.azure.identity.AzureCliCredentialBuilder;
-import com.azure.identity.ChainedTokenCredential;
-import com.azure.identity.ChainedTokenCredentialBuilder;
 import com.azure.identity.ClientSecretCredentialBuilder;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -735,7 +734,7 @@ private static void runIngestV2Sample(@NotNull ConfigJson config) {
         }
 
         System.out.println("Running ingest-v2 quickstart sample...");
-        ChainedTokenCredential credential = buildIngestV2Credential(ingestV2Config);
+        TokenCredential credential = buildIngestV2Credential(ingestV2Config);
 
         try (QueuedIngestClient queuedIngestClient = QueuedIngestClientBuilder.create(clusterPath)
                 .withAuthentication(credential)
@@ -757,25 +756,23 @@ private static void runIngestV2Sample(@NotNull ConfigJson config) {
         }
     }
 
-    private static ChainedTokenCredential buildIngestV2Credential(@NotNull IngestV2QuickstartConfig config) {
+    private static TokenCredential buildIngestV2Credential(@NotNull IngestV2QuickstartConfig config) {
         AuthenticationModeOptions mode = config.getAuthModeOverride();
         if (mode == null) {
             mode = AuthenticationModeOptions.USER_PROMPT;
         }
-        ChainedTokenCredentialBuilder builder = new ChainedTokenCredentialBuilder();
         if (mode == AuthenticationModeOptions.APP_KEY) {
             if (StringUtils.isBlank(config.getAppId()) || StringUtils.isBlank(config.getAppKey()) || StringUtils.isBlank(config.getTenantId())) {
                 Utils.errorHandler("AppKey authentication requires 'APP_ID', 'APP_KEY', and 'APP_TENANT' environment variables or ingestV2 overrides.");
             }
-            builder.addFirst(new ClientSecretCredentialBuilder()
+            return new ClientSecretCredentialBuilder()
                     .clientId(config.getAppId())
                     .clientSecret(config.getAppKey())
                     .tenantId(config.getTenantId())
-                    .build());
+                    .build();
         } else {
-            builder.addFirst(new AzureCliCredentialBuilder().build());
+            return new AzureCliCredentialBuilder().build();
         }
-        return builder.build();
     }
 
     private static @NotNull List<CompletableFuture<Void>> ingestV2FromStreams(ConfigJson config, IngestV2QuickstartConfig ingestV2Config,
@@ -835,7 +832,7 @@ private static ChainedTokenCredential buildIngestV2Credential(@NotNull IngestV2Q
                                                                            @NotNull QueuedIngestClient queuedIngestClient) {
         System.out.println("\n=== Queued batch ingestion: Upload local files to blob, then ingest (ingest-v2) ===");
         String clusterPath = ingestV2Config.getClusterPath();
-        ChainedTokenCredential credential = buildIngestV2Credential(ingestV2Config);
+        TokenCredential credential = buildIngestV2Credential(ingestV2Config);
 
         ConfigurationCache configCache = DefaultConfigurationCache.create(
                 clusterPath,