diff --git a/backend/managers/gameLauncher.js b/backend/managers/gameLauncher.js
index 9a8a317..bcbe784 100644
--- a/backend/managers/gameLauncher.js
+++ b/backend/managers/gameLauncher.js
@@ -285,12 +285,30 @@ exec "$REAL_JAVA" "\${ARGS[@]}"
    const gpuEnv = setupGpuEnvironment(gpuPreference);
    Object.assign(env, gpuEnv);
 
-   // Disable glibc heap validation on Linux to prevent false positive
-   // "free(): invalid pointer" crashes on Steam Deck and Ubuntu LTS
-   // This doesn't hide real bugs - the same binary works on other systems
+   // Linux memory allocator fixes for "free(): invalid pointer" crashes
+   // on Steam Deck (glibc 2.41) and Ubuntu LTS
    if (process.platform === 'linux') {
+     // Option 1: Disable glibc heap validation
      env.MALLOC_CHECK_ = '0';
-     console.log('Linux detected: Setting MALLOC_CHECK_=0 to disable glibc heap validation');
+
+     // Option 2: Try to use jemalloc if available (more robust allocator)
+     // User can set HYTALE_USE_JEMALLOC=1 to enable
+     if (process.env.HYTALE_USE_JEMALLOC === '1') {
+       const jemalloc = require('fs').existsSync('/usr/lib/libjemalloc.so.2')
+         ? '/usr/lib/libjemalloc.so.2'
+         : require('fs').existsSync('/usr/lib/x86_64-linux-gnu/libjemalloc.so.2')
+           ? '/usr/lib/x86_64-linux-gnu/libjemalloc.so.2'
+           : null;
+
+       if (jemalloc) {
+         env.LD_PRELOAD = jemalloc + (env.LD_PRELOAD ? ':' + env.LD_PRELOAD : '');
+         console.log(`Linux: Using jemalloc allocator (${jemalloc})`);
+       } else {
+         console.log('Linux: jemalloc not found, using glibc with MALLOC_CHECK_=0');
+       }
+     } else {
+       console.log('Linux: Using glibc with MALLOC_CHECK_=0 (set HYTALE_USE_JEMALLOC=1 to try jemalloc)');
+     }
    }
 
   try {
diff --git a/backend/utils/clientPatcher.js b/backend/utils/clientPatcher.js
index 332a7a4..21f6116 100644
--- a/backend/utils/clientPatcher.js
+++ b/backend/utils/clientPatcher.js
@@ -245,6 +245,10 @@ class ClientPatcher {
   /**
    * Apply all domain patches using length-prefixed format
    * This is the main patching method for variable-length domains
+   *
+   * Debug env vars:
+   *   HYTALE_SKIP_SENTRY_PATCH=1 - Skip sentry URL patch (biggest size change)
+   *   HYTALE_SKIP_SUBDOMAIN_PATCH=1 - Skip subdomain prefix patches
    */
   applyDomainPatches(data, domain, protocol = 'https://') {
     let result = Buffer.from(data);
@@ -253,20 +257,24 @@ class ClientPatcher {
 
     console.log(`  Patching strategy: ${strategy.description}`);
 
-    // 1. Patch telemetry/sentry URL
-    const oldSentry = 'https://ca900df42fcf57d4dd8401a86ddd7da2@sentry.hytale.com/2';
-    const newSentry = `${protocol}t@${domain}/2`;
+    // 1. Patch telemetry/sentry URL (skip if debugging)
+    if (process.env.HYTALE_SKIP_SENTRY_PATCH === '1') {
+      console.log(`  Skipping sentry patch (HYTALE_SKIP_SENTRY_PATCH=1)`);
+    } else {
+      const oldSentry = 'https://ca900df42fcf57d4dd8401a86ddd7da2@sentry.hytale.com/2';
+      const newSentry = `${protocol}t@${domain}/2`;
 
-    console.log(`  Patching sentry: ${oldSentry.slice(0, 30)}... -> ${newSentry}`);
-    const sentryResult = this.replaceBytes(
-        result,
-        this.stringToLengthPrefixed(oldSentry),
-        this.stringToLengthPrefixed(newSentry)
-    );
-    result = sentryResult.buffer;
-    if (sentryResult.count > 0) {
-      console.log(`    Replaced ${sentryResult.count} sentry occurrence(s)`);
-      totalCount += sentryResult.count;
+      console.log(`  Patching sentry: ${oldSentry.slice(0, 30)}... -> ${newSentry}`);
+      const sentryResult = this.replaceBytes(
+          result,
+          this.stringToLengthPrefixed(oldSentry),
+          this.stringToLengthPrefixed(newSentry)
+      );
+      result = sentryResult.buffer;
+      if (sentryResult.count > 0) {
+        console.log(`    Replaced ${sentryResult.count} sentry occurrence(s)`);
+        totalCount += sentryResult.count;
+      }
     }
 
     // 2. Patch main domain (hytale.com -> mainDomain)
@@ -282,21 +290,25 @@ class ClientPatcher {
       totalCount += domainResult.count;
     }
 
-    // 3. Patch subdomain prefixes
-    const subdomains = ['https://tools.', 'https://sessions.', 'https://account-data.', 'https://telemetry.'];
-    const newSubdomainPrefix = protocol + strategy.subdomainPrefix;
+    // 3. Patch subdomain prefixes (skip if debugging)
+    if (process.env.HYTALE_SKIP_SUBDOMAIN_PATCH === '1') {
+      console.log(`  Skipping subdomain patches (HYTALE_SKIP_SUBDOMAIN_PATCH=1)`);
+    } else {
+      const subdomains = ['https://tools.', 'https://sessions.', 'https://account-data.', 'https://telemetry.'];
+      const newSubdomainPrefix = protocol + strategy.subdomainPrefix;
 
-    for (const sub of subdomains) {
-      console.log(`  Patching subdomain: ${sub} -> ${newSubdomainPrefix}`);
-      const subResult = this.replaceBytes(
-          result,
-          this.stringToLengthPrefixed(sub),
-          this.stringToLengthPrefixed(newSubdomainPrefix)
-      );
-      result = subResult.buffer;
-      if (subResult.count > 0) {
-        console.log(`    Replaced ${subResult.count} occurrence(s)`);
-        totalCount += subResult.count;
+      for (const sub of subdomains) {
+        console.log(`  Patching subdomain: ${sub} -> ${newSubdomainPrefix}`);
+        const subResult = this.replaceBytes(
+            result,
+            this.stringToLengthPrefixed(sub),
+            this.stringToLengthPrefixed(newSubdomainPrefix)
+        );
+        result = subResult.buffer;
+        if (subResult.count > 0) {
+          console.log(`    Replaced ${subResult.count} occurrence(s)`);
+          totalCount += subResult.count;
+        }
       }
     }