diff --git a/.github/workflows/flutter-build.yml b/.github/workflows/flutter-build.yml
index abaf63ba1..f2fb40643 100644
--- a/.github/workflows/flutter-build.yml
+++ b/.github/workflows/flutter-build.yml
@@ -405,6 +405,11 @@ jobs:
         # it also names payload that must never be renamed, such as librustdesk.dll
         # and drivers\RustDeskPrinterDriver.
         #
+        # --template also puts the files a custom client replaces in their own
+        # cabinet, so rebranding rebuilds a few hundred KB rather than recompressing
+        # the whole payload. The shipped msi above is built without it and is
+        # unaffected.
+        #
         # Building the arm64 template on the native arm64 runner is what makes ARM
         # custom clients possible at all: the build agents are x64 and cannot run
         # preprocess.py against an ARM exe.
@@ -413,8 +418,18 @@ jobs:
           git checkout -- res/msi
           cp -r ./rustdesk ./rustdesk-msi-template
           mv ./rustdesk-msi-template/rustdesk.exe ./rustdesk-msi-template/RDAPPNAM.exe
+          # A stock build ships none of the files a custom client replaces, so the
+          # template needs a placeholder for each to have a File row to patch. The
+          # branding assets install only when the patcher says the customer supplied
+          # one, so an unused placeholder is never installed.
+          Set-Content -Path ./rustdesk-msi-template/custom.txt -Value 'placeholder' -NoNewline
+          $assets = './rustdesk-msi-template/data/flutter_assets/assets'
+          New-Item -ItemType Directory -Force -Path $assets | Out-Null
+          foreach ($a in 'icon.ico','icon.png','logo.png','logo_light.png','logo_dark.png') {
+            Set-Content -Path "$assets/$a" -Value 'placeholder' -NoNewline
+          }
           pushd ./res/msi
-          python preprocess.py --arp -d ../../rustdesk-msi-template --app-name RDAPPNAM
+          python preprocess.py --arp --template -d ../../rustdesk-msi-template --app-name RDAPPNAM
           $msiPlatform = if ('${{ matrix.job.arch }}' -eq 'aarch64') { 'ARM64' } else { 'x64' }
           msbuild msi.sln -t:clean -p:Configuration=Release -p:Platform=$msiPlatform
           msbuild msi.sln -p:Configuration=Release -p:Platform=$msiPlatform /p:TargetVersion=Windows10
diff --git a/res/msi/Package/Package.wxs b/res/msi/Package/Package.wxs
index e11756a65..78cdf837b 100644
--- a/res/msi/Package/Package.wxs
+++ b/res/msi/Package/Package.wxs
@@ -13,6 +13,12 @@
 		<PropertyRef Id="AddRemovePropertiesFile" />
 
 		<Media Id="1" Cabinet="cab1.cab" EmbedCab="yes" CompressionLevel="high" />
+		<!--$Media2Start$-->
+		<!-- preprocess.py in template mode adds a second cabinet here, holding only
+		     the files that differ per customer, so a custom client can be produced by
+		     rebuilding that small cabinet instead of the whole package. The shipped
+		     msi is built without template mode and keeps a single cabinet. -->
+		<!--$Media2End$-->
 		<Icon Id="AppIcon" SourceFile="Resources\icon.ico" />
 
 		<!-- User Interface -->
diff --git a/res/msi/preprocess.py b/res/msi/preprocess.py
index 3f52aceb8..90190d028 100644
--- a/res/msi/preprocess.py
+++ b/res/msi/preprocess.py
@@ -65,6 +65,14 @@ def make_parser():
     parser.add_argument(
         "-c", "--custom", action="store_true", help="Is custom client", default=False
     )
+    parser.add_argument(
+        "--template",
+        action="store_true",
+        default=False,
+        help="Build a template to be patched per customer rather than a finished "
+        "package: puts the files a custom client replaces in their own cabinet, so "
+        "rebranding rebuilds a few hundred KB instead of the whole payload.",
+    )
     parser.add_argument(
         "--conn-type",
         type=str,
@@ -90,6 +98,43 @@ def make_parser():
     return parser
 
 
+# Files a custom client replaces. Kept in their own cabinet by --template so that
+# rebranding rebuilds a few hundred KB instead of recompressing the whole payload.
+# The app executable is handled separately: it has its own component in RustDesk.wxs.
+#
+# A template has to ship a placeholder for each of these so there is a File row to
+# patch, but the branding assets are optional for a customer and a stock build has
+# none of them at all. So each optional one installs only when its property is set,
+# which the patcher does for the files a customer actually supplied. Otherwise a
+# customer without a logo would install the placeholder, where today they get no
+# logo at all -- the client treats a missing asset as "no logo".
+PER_CUSTOMER_DISK_ID = 2
+PER_CUSTOMER_FILES = {
+    # relative path -> property gating installation, or None if always installed
+    "custom.txt": None,
+    "data/flutter_assets/assets/icon.ico": "CC_HAS_ICON_ICO",
+    "data/flutter_assets/assets/icon.png": "CC_HAS_ICON_PNG",
+    "data/flutter_assets/assets/logo.png": "CC_HAS_LOGO",
+    "data/flutter_assets/assets/logo_light.png": "CC_HAS_LOGO_LIGHT",
+    "data/flutter_assets/assets/logo_dark.png": "CC_HAS_LOGO_DARK",
+}
+
+
+def normalize_relative(relative_path):
+    path = relative_path.replace("\\", "/")
+    while path.startswith("./"):
+        path = path[2:]
+    return path.lower()
+
+
+def is_per_customer(relative_path):
+    return normalize_relative(relative_path) in PER_CUSTOMER_FILES
+
+
+def per_customer_condition(relative_path):
+    return PER_CUSTOMER_FILES.get(normalize_relative(relative_path))
+
+
 def read_lines_and_start_index(file_path, tag_start, tag_end):
     with open(file_path, "r", encoding="utf-8") as f:
         lines = f.readlines()
@@ -110,7 +155,7 @@ def read_lines_and_start_index(file_path, tag_start, tag_end):
     return lines, index_start
 
 
-def insert_components_between_tags(lines, index_start, app_name, dist_dir):
+def insert_components_between_tags(lines, index_start, app_name, dist_dir, template=False):
     indent = g_indent_unit * 3
     path = Path(dist_dir)
     idx = 1
@@ -124,12 +169,23 @@ def insert_components_between_tags(lines, index_start, app_name, dist_dir):
             if subdir != ".":
                 dir_attr = f'Subdirectory="{subdir}"'
 
+            relative = file_path.relative_to(path).as_posix()
+            disk_attr = ""
+            condition_attr = ""
+            if template and is_per_customer(relative):
+                disk_attr = f' DiskId="{PER_CUSTOMER_DISK_ID}"'
+                # Branding assets are optional, and the template only carries a
+                # placeholder, so install one only when the customer supplied it.
+                condition = per_customer_condition(relative)
+                if condition:
+                    condition_attr = f' Condition="{condition} = 1"'
+
             # Don't generate Component Id and File Id like 'Component_{idx}' and 'File_{idx}'
             # because it will cause error
             # "Error WIX0130	The primary key 'xxxx' is duplicated in table 'Directory'"
             to_insert_lines = f"""
-{indent}<Component Guid="{uuid.uuid4()}" {dir_attr}>
-{indent}{g_indent_unit}<File Source="{file_path.as_posix()}" KeyPath="yes" Checksum="yes" />
+{indent}<Component Guid="{uuid.uuid4()}" {dir_attr}{condition_attr}>
+{indent}{g_indent_unit}<File Source="{file_path.as_posix()}" KeyPath="yes" Checksum="yes"{disk_attr} />
 {indent}</Component>
 """
             lines.insert(index_start + 1, to_insert_lines[1:])
@@ -138,17 +194,52 @@ def insert_components_between_tags(lines, index_start, app_name, dist_dir):
     return True
 
 
-def gen_auto_component(app_name, dist_dir):
+def gen_auto_component(app_name, dist_dir, template=False):
     return gen_content_between_tags(
         "Package/Components/RustDesk.wxs",
         "<!--$AutoComonentStart$-->",
         "<!--$AutoComponentEnd$-->",
         lambda lines, index_start: insert_components_between_tags(
-            lines, index_start, app_name, dist_dir
+            lines, index_start, app_name, dist_dir, template
         ),
     )
 
 
+def gen_media2():
+    """Second cabinet holding only what a custom client replaces."""
+
+    def func(lines, index_start):
+        indent = g_indent_unit * 2
+        lines.insert(
+            index_start + 1,
+            f'{indent}<Media Id="{PER_CUSTOMER_DISK_ID}" Cabinet="cab2.cab"'
+            ' EmbedCab="yes" CompressionLevel="high" />\n',
+        )
+        return lines
+
+    return gen_content_between_tags(
+        "Package/Package.wxs", "<!--$Media2Start$-->", "<!--$Media2End$-->", func
+    )
+
+
+def put_app_exe_on_media2():
+    """The app executable has its own component, so it is moved by name."""
+    target = Path(sys.argv[0]).parent.joinpath("Package/Components/RustDesk.wxs")
+    with open(target, "r", encoding="utf-8") as f:
+        content = f.read()
+    old = '<File Id="App.exe" Name="$(var.Product).exe" KeyPath="yes" Checksum="yes">'
+    new = (
+        '<File Id="App.exe" Name="$(var.Product).exe" KeyPath="yes" Checksum="yes"'
+        f' DiskId="{PER_CUSTOMER_DISK_ID}">'
+    )
+    if content.count(old) != 1:
+        print(f"Error: expected exactly one App.exe File element, found {content.count(old)}")
+        return False
+    with open(target, "w", encoding="utf-8") as f:
+        f.write(content.replace(old, new))
+    return True
+
+
 def gen_pre_vars(args, dist_dir):
     def func(lines, index_start):
         upgrade_code = uuid.uuid5(uuid.NAMESPACE_OID, app_name + ".exe")
@@ -537,7 +628,13 @@ if __name__ == "__main__":
     if not gen_conn_type(args):
         sys.exit(-1)
 
-    if not gen_auto_component(app_name, dist_dir):
+    if args.template:
+        if not gen_media2():
+            sys.exit(-1)
+        if not put_app_exe_on_media2():
+            sys.exit(-1)
+
+    if not gen_auto_component(app_name, dist_dir, args.template):
         sys.exit(-1)
 
     if not gen_custom_dialog_bitmaps():