diff --git a/configs/advantech/icam-540.yaml b/configs/advantech/icam-540.yaml
deleted file mode 100644
index a047a14..0000000
--- a/configs/advantech/icam-540.yaml
+++ /dev/null
@@ -1,83 +0,0 @@
-supported_targets:
-- icam-540
-default_target: icam-540
-src_dir: ../../
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-ext-dev
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-    icam-540:
-      packages: {}
-extensions:
-  avocado-ext-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages:
-      i2c-tools: '*'
-      pylon: '*'
-      pylon-dev: '*'
-      v4l-utils: '*'
-      opencv: '*'
-      gstreamer1.0: '*'
-      gstreamer1.0-plugins-base-videoconvertscale: '*'
-      gstreamer1.0-plugins-good-jpeg: '*'
-      gstreamer1.0-plugins-good-rtp: '*'
-      gstreamer1.0-plugins-good-udp: '*'
-      gstreamer1.0-plugins-good-multipart: '*'
-      gstreamer1.0-plugins-base-tcp: '*'
-      gstreamer1.0-plugins-bad-mpegtsmux: '*'
-      gstreamer1.0-plugins-nvvidconv: '*'
-      gstreamer1.0-plugins-nvjpeg: '*'
-      gst-plugin-pylon: '*'
-      usbutils: '*'
-      udev-hwdb: '*'
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  icam-540:
-    packages:
-      nativesdk-util-linux-mount: '*'
-      nativesdk-tegraflash-tools: '*'
-    container_args:
-    - --network=host
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-provision_profiles:
-  tegraflash:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/configs/default.yaml b/configs/default.yaml
index 7894fb9..25674ff 100644
--- a/configs/default.yaml
+++ b/configs/default.yaml
@@ -25,9 +25,7 @@ runtimes:
       - config
       - app
     packages:
-      avocado-img-bootfiles: "*"
-      avocado-img-rootfs: "*"
-      avocado-img-initramfs: "*"
+      avocado-runtime: "{{ avocado.distro.version }}"
 
 ##
 ## Extensions
@@ -57,14 +55,14 @@ extensions:
       - confext
     version: "0.1.0"
 
-  # Install application dependencies
-    # packages:
-#curl = "*"
-#iperf3 = "*"
+    # Install additional application dependencies
+    #packages:
+      #curl: "*"
+      #iperf3: "*"
 
-# Generated default config extension
-# Use or modify this to configure "real" user accounts (passwd, shadow, group)
-# or configure other system services
+  # Generated default config extension
+  # Use or modify this to configure "real" user accounts (passwd, shadow, group)
+  # or configure other system services
   config:
     types:
       - confext
@@ -82,34 +80,11 @@ extensions:
 sdk:
   image: "docker.io/avocadolinux/sdk:{{ config.distro.channel }}"
 
+  container_args:
+    - --privileged
+    - --network=host
+    - -v /dev:/dev
+    - -v /sys:/sys
+
   packages:
     avocado-sdk-toolchain: "{{ config.distro.version }}"
-
-  {target}:
-    container_args:
-      - --network=host
-
-##
-## Provisioning
-##
-
-# When provisioning using usb or sd provisioning profiles, set extra sdk
-# container arguments to allow access to these devices
-
-provision_profiles:
-  usb:
-    container_args:
-      - -v
-      - /dev:/dev
-      - -v
-      - /sys:/sys:ro
-      - --privileged
-
-  sd:
-    container_args:
-      - -v
-      - /dev:/dev
-      - -v
-      - /sys:/sys:ro
-      - --privileged
-
diff --git a/configs/nvidia/jetson-orin-nano-devkit.yaml b/configs/nvidia/jetson-orin-nano-devkit.yaml
deleted file mode 100644
index 350e072..0000000
--- a/configs/nvidia/jetson-orin-nano-devkit.yaml
+++ /dev/null
@@ -1,59 +0,0 @@
-default_target: jetson-orin-nano-devkit
-supported_targets:
-- jetson-orin-nano-devkit
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-    jetson-orin-nano-devkit:
-      packages: {}
-extensions:
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages: {}
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  jetson-orin-nano-devkit:
-    container_args:
-    - --network=host
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-    packages:
-      nativesdk-util-linux-mount: '*'
-      nativesdk-tegraflash-tools: '*'
-provision_profiles:
-  tegraflash:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/configs/raspberry-pi/raspberrypi-4-model-b.yaml b/configs/raspberry-pi/raspberrypi-4-model-b.yaml
deleted file mode 100644
index d7ac2a9..0000000
--- a/configs/raspberry-pi/raspberrypi-4-model-b.yaml
+++ /dev/null
@@ -1,66 +0,0 @@
-default_target: raspberrypi4
-supported_targets:
-- raspberrypi4
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-ext-dev
-      - avocado-ext-sshd-dev
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-extensions:
-  avocado-ext-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-ext-sshd-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages: {}
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  raspberrypi4:
-    container_args:
-    - --network=host
-provision_profiles:
-  img:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-  sd:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/configs/raspberry-pi/raspberrypi-5.yaml b/configs/raspberry-pi/raspberrypi-5.yaml
deleted file mode 100644
index 7e17640..0000000
--- a/configs/raspberry-pi/raspberrypi-5.yaml
+++ /dev/null
@@ -1,66 +0,0 @@
-default_target: raspberrypi5
-supported_targets:
-- raspberrypi5
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-ext-dev
-      - avocado-ext-sshd-dev
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-extensions:
-  avocado-ext-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-ext-sshd-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages: {}
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  raspberrypi5:
-    container_args:
-    - --network=host
-provision_profiles:
-  img:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-  sd:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/configs/seeed/reterminal-dm.yaml b/configs/seeed/reterminal-dm.yaml
deleted file mode 100644
index e522e1b..0000000
--- a/configs/seeed/reterminal-dm.yaml
+++ /dev/null
@@ -1,66 +0,0 @@
-default_target: reterminal-dm
-supported_targets:
-- reterminal-dm
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-ext-dev
-      - avocado-ext-sshd-dev
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-extensions:
-  avocado-ext-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-ext-sshd-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages: {}
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  reterminal-dm:
-    container_args:
-    - --network=host
-provision_profiles:
-  usb:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-  sd:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/configs/seeed/reterminal.yaml b/configs/seeed/reterminal.yaml
deleted file mode 100644
index a01cdd7..0000000
--- a/configs/seeed/reterminal.yaml
+++ /dev/null
@@ -1,66 +0,0 @@
-default_target: reterminal
-supported_targets:
-- reterminal
-distro:
-  channel: apollo-edge
-  version: 0.1.0
-runtimes:
-  dev:
-    extensions:
-      - avocado-ext-dev
-      - avocado-ext-sshd-dev
-      - avocado-bsp-{{ avocado.target }}
-      - config
-      - app
-    packages:
-      avocado-img-bootfiles: '*'
-      avocado-img-rootfs: '*'
-      avocado-img-initramfs: '*'
-extensions:
-  avocado-ext-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-ext-sshd-dev:
-    source:
-      type: package
-      version: '*'
-  avocado-bsp-{{ avocado.target }}:
-    source:
-      type: package
-      version: '*'
-  app:
-    types:
-    - sysext
-    - confext
-    version: 0.1.0
-    packages: {}
-  config:
-    types:
-    - confext
-    version: 0.1.0
-    users:
-      root:
-        password: ''
-sdk:
-  image: docker.io/avocadolinux/sdk:{{ config.distro.channel }}
-  packages:
-    avocado-sdk-toolchain: "{{ config.distro.version }}"
-  reterminal:
-    container_args:
-    - --network=host
-provision_profiles:
-  usb:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
-  sd:
-    container_args:
-    - -v
-    - /dev:/dev
-    - -v
-    - /sys:/sys:ro
-    - --privileged
diff --git a/src/commands/build.rs b/src/commands/build.rs
index 6a2e203..6c9193c 100644
--- a/src/commands/build.rs
+++ b/src/commands/build.rs
@@ -1662,7 +1662,8 @@ echo "Successfully created image for versioned extension '$EXT_NAME-$EXT_VERSION
             .and_then(|ext| ext.get(ext_name))
         {
             // Check if this local extension has dependencies
-            if let Some(dependencies) = ext_config.get("packages").and_then(|d| d.as_mapping()) {
+            let packages_value = ext_config.get("packages");
+            if let Some(dependencies) = packages_value.and_then(|d| d.as_mapping()) {
                 for (_dep_name, dep_spec) in dependencies {
                     // Check for extension dependency
                     if let Some(nested_ext_name) =
@@ -1702,6 +1703,24 @@ echo "Successfully created image for versioned extension '$EXT_NAME-$EXT_VERSION
                         }
                     }
                 }
+            } else if let Some(deps_value) = packages_value {
+                // packages field exists but is not a YAML mapping — detect common syntax mistakes
+                if !deps_value.is_null() {
+                    let value_str = serde_yaml::to_string(deps_value)
+                        .unwrap_or_else(|_| format!("{deps_value:?}"));
+                    let hint = if value_str.contains('=') {
+                        "\n\nIt looks like '=' was used instead of ':'. YAML uses ':' for key-value pairs.\n\
+                         Example:\n  packages:\n    curl: \"*\"\n    iperf3: \"*\""
+                    } else {
+                        "\n\nExpected a YAML mapping (key: value pairs).\n\
+                         Example:\n  packages:\n    curl: \"*\"\n    iperf3: \"*\""
+                    };
+                    return Err(anyhow::anyhow!(
+                        "Invalid 'packages' format in extension '{ext_name}': \
+                         expected a mapping but got: {}{hint}",
+                        value_str.trim()
+                    ));
+                }
             }
         }
 
diff --git a/src/commands/ext/install.rs b/src/commands/ext/install.rs
index f4feade..a5b6787 100644
--- a/src/commands/ext/install.rs
+++ b/src/commands/ext/install.rs
@@ -697,6 +697,24 @@ $DNF_SDK_HOST \
                     OutputLevel::Normal,
                 );
             }
+        } else if let Some(deps_value) = dependencies {
+            // packages field exists but is not a YAML mapping — detect common syntax mistakes
+            if !deps_value.is_null() {
+                let value_str =
+                    serde_yaml::to_string(deps_value).unwrap_or_else(|_| format!("{deps_value:?}"));
+                let hint = if value_str.contains('=') {
+                    "\n\nIt looks like '=' was used instead of ':'. YAML uses ':' for key-value pairs.\n\
+                     Example:\n  packages:\n    curl: \"*\"\n    iperf3: \"*\""
+                } else {
+                    "\n\nExpected a YAML mapping (key: value pairs).\n\
+                     Example:\n  packages:\n    curl: \"*\"\n    iperf3: \"*\""
+                };
+                return Err(anyhow::anyhow!(
+                    "Invalid 'packages' format in extension '{extension}': \
+                     expected a mapping but got: {}{hint}",
+                    value_str.trim()
+                ));
+            }
         } else if self.verbose {
             print_debug(
                 &format!("No dependencies defined for extension '{extension}'."),
diff --git a/src/commands/init.rs b/src/commands/init.rs
index 55a01c0..aa23f64 100644
--- a/src/commands/init.rs
+++ b/src/commands/init.rs
@@ -150,30 +150,11 @@ impl InitCommand {
     /// # Returns
     /// * The configuration template content as a string
     fn load_config_template(target: &str) -> String {
-        // Try to load YAML config first, fall back to default with target substitution
-        let yaml_content = match target {
-            "reterminal" => Some(include_str!("../../configs/seeed/reterminal.yaml")),
-            "reterminal-dm" => Some(include_str!("../../configs/seeed/reterminal-dm.yaml")),
-            "jetson-orin-nano-devkit" => Some(include_str!(
-                "../../configs/nvidia/jetson-orin-nano-devkit.yaml"
-            )),
-            "raspberrypi4" => Some(include_str!(
-                "../../configs/raspberry-pi/raspberrypi-4-model-b.yaml"
-            )),
-            "raspberrypi5" => Some(include_str!(
-                "../../configs/raspberry-pi/raspberrypi-5.yaml"
-            )),
-            "icam-540" => Some(include_str!("../../configs/advantech/icam-540.yaml")),
-            _ => None,
-        };
-
-        if let Some(content) = yaml_content {
-            content.to_string()
-        } else {
-            // Use default YAML template and substitute the target
-            let default_template = include_str!("../../configs/default.yaml");
-            default_template.replace("{target}", target)
-        }
+        // All targets start from the default config template.
+        // To add target-specific config additions in the future, create a YAML file at
+        // configs/additions/<target>.yaml and add an include_str! match arm here.
+        let default_template = include_str!("../../configs/default.yaml");
+        default_template.replace("{target}", target)
     }
 
     /// Checks if a reference exists in the repository.
@@ -1052,9 +1033,7 @@ mod tests {
         assert!(content.contains("runtimes:"));
         assert!(content.contains("dev:"));
         assert!(content.contains("packages:"));
-        assert!(content.contains("avocado-img-bootfiles:"));
-        assert!(content.contains("avocado-img-rootfs:"));
-        assert!(content.contains("avocado-img-initramfs:"));
+        assert!(content.contains("avocado-runtime:"));
         assert!(content.contains("avocado-ext-dev:"));
         assert!(content.contains("type: package"));
         assert!(
@@ -1220,45 +1199,18 @@ mod tests {
         let default_template =
             include_str!("../../configs/default.yaml").replace("{target}", "test-target");
         validate_ext_versions(&default_template, "default.yaml");
-
-        // Test reterminal
-        let reterminal = include_str!("../../configs/seeed/reterminal.yaml");
-        validate_ext_versions(reterminal, "reterminal.yaml");
-
-        // Test reterminal-dm
-        let reterminal_dm = include_str!("../../configs/seeed/reterminal-dm.yaml");
-        validate_ext_versions(reterminal_dm, "reterminal-dm.yaml");
-
-        // Test jetson-orin-nano-devkit
-        let jetson = include_str!("../../configs/nvidia/jetson-orin-nano-devkit.yaml");
-        validate_ext_versions(jetson, "jetson-orin-nano-devkit.yaml");
-
-        // Test raspberrypi4
-        let rpi4 = include_str!("../../configs/raspberry-pi/raspberrypi-4-model-b.yaml");
-        validate_ext_versions(rpi4, "raspberrypi-4-model-b.yaml");
-
-        // Test raspberrypi5
-        let rpi5 = include_str!("../../configs/raspberry-pi/raspberrypi-5.yaml");
-        validate_ext_versions(rpi5, "raspberrypi-5.yaml");
-
-        // Test icam-540
-        let icam = include_str!("../../configs/advantech/icam-540.yaml");
-        validate_ext_versions(icam, "icam-540.yaml");
     }
 
     #[tokio::test]
     async fn test_generated_configs_have_ext_versions() {
-        // Test that configs generated for all supported targets have versions
+        // Test that configs generated for various targets have versions.
+        // All targets use the default template with target substitution.
         let targets = vec![
             "qemux86-64",
             "qemuarm64",
-            "reterminal",
-            "reterminal-dm",
-            "jetson-orin-nano-devkit",
             "raspberrypi4",
-            "raspberrypi5",
-            "icam-540",
-            "custom-target", // This uses the default template
+            "jetson-orin-nano-devkit",
+            "custom-target",
         ];
 
         for target in targets {