diff --git a/README.md b/README.md
index 793dfcb..9921b15 100644
--- a/README.md
+++ b/README.md
@@ -169,12 +169,12 @@ Many of the framework's built in features may be enabled or disabled as required
 Customize the settings as you see fit. A value of 0 will disable the specified feature:
 
 ```ini
-    -D FT_PROJECT=1
-    -D FT_SECURITY=1
-    -D FT_MQTT=1
-    -D FT_NTP=1
-    -D FT_OTA=1
-    -D FT_UPLOAD_FIRMWARE=1
+  -D FT_PROJECT=1
+  -D FT_SECURITY=1
+  -D FT_MQTT=1
+  -D FT_NTP=1
+  -D FT_OTA=1
+  -D FT_UPLOAD_FIRMWARE=1
 ```
 
 Flag               | Description
@@ -193,9 +193,9 @@ The framework has built-in factory settings which act as default values for the
 Customize the settings as you see fit, for example you might configure your home WiFi network as the factory default:
 
 ```ini
-    -D FACTORY_WIFI_SSID=\"My Awesome WiFi Network\"
-    -D FACTORY_WIFI_PASSWORD=\"secret\"
-    -D FACTORY_WIFI_HOSTNAME=\"awesome_light_controller\"
+  -D FACTORY_WIFI_SSID=\"My Awesome WiFi Network\"
+  -D FACTORY_WIFI_PASSWORD=\"secret\"
+  -D FACTORY_WIFI_HOSTNAME=\"awesome_light_controller\"
 ```
 
 ### Default access point settings
@@ -221,15 +221,31 @@ It is recommended that you change the user credentials from their defaults bette
 Changing factory time zone setting is a common requirement. This requires a little effort because the time zone name and POSIX format are stored as separate values for the moment. The time zone names and POSIX formats are contained in the UI code in [TZ.tsx](interface/src/ntp/TZ.tsx). Take the appropriate pair of values from there, for example, for Los Angeles you would use:
 
 ```ini
-    -D FACTORY_NTP_TIME_ZONE_LABEL=\"America/Los_Angeles\"
-    -D FACTORY_NTP_TIME_ZONE_FORMAT=\"PST8PDT,M3.2.0,M11.1.0\"
+  -D FACTORY_NTP_TIME_ZONE_LABEL=\"America/Los_Angeles\"
+  -D FACTORY_NTP_TIME_ZONE_FORMAT=\"PST8PDT,M3.2.0,M11.1.0\"
 ```
 
-### Device ID factory defaults
+### Placeholder substitution
 
-If not overridden with a build flag, the framework will use the device ID to generate factory defaults for settings such as the JWT secret and MQTT client ID. 
+Various settings support placeholder substitution, indicated by comments in [factory_settings.ini](factory_settings.ini). This can be particularly useful where settings need to be unique, such as the Access Point SSID or MQTT client id. The following placeholders are supported:
 
-> **Tip**: Random values are generally better defaults for these settings, so it is recommended you leave these flags undefined.
+Placeholder  | Substituted value 
+-----------  | -----------------
+#{platform}  | The microcontroller platform, e.g. "esp32" or "esp8266"
+#{unique_id} | A unique identifier derived from the MAC address, e.g. "0b0a859d6816"
+#{random}    | A random number encoded as a hex string, e.g. "55722f94"
+
+You may use SettingValue::format in your own code if you require the use of these placeholders. This is demonstrated in the demo project:
+
+```cpp
+  static StateUpdateResult update(JsonObject& root, LightMqttSettings& settings) {
+    settings.mqttPath = root["mqtt_path"] | SettingValue::format("homeassistant/light/#{unique_id}");
+    settings.name = root["name"] | SettingValue::format("light-#{unique_id}");
+    settings.uniqueId = root["unique_id"] | SettingValue::format("light-#{unique_id}");
+    return StateUpdateResult::CHANGED;
+  }
+};
+```
 
 ## Building for different devices
 
diff --git a/factory_settings.ini b/factory_settings.ini
index 4cbcf5c..db8744d 100644
--- a/factory_settings.ini
+++ b/factory_settings.ini
@@ -1,48 +1,51 @@
+; The indicated settings support placeholder substitution as follows:
+;
+;  #{platform} - The microcontroller platform, e.g. "esp32" or "esp8266"
+;  #{unique_id} - A unique identifier derived from the MAC address, e.g. "0b0a859d6816"
+;  #{random} - A random number encoded as a hex string, e.g. "55722f94"
+
 [factory_settings]
-build_flags = 
-    ; WiFi settings
-    -D FACTORY_WIFI_SSID=\"\"
-    -D FACTORY_WIFI_PASSWORD=\"\"
-    ; if unspecified the devices hardware ID will be used
-    ; -D FACTORY_WIFI_HOSTNAME=\"esp-react\"  
+build_flags =
+  ; WiFi settings
+  -D FACTORY_WIFI_SSID=\"\"
+  -D FACTORY_WIFI_PASSWORD=\"\"
+  -D FACTORY_WIFI_HOSTNAME=\"#{platform}-#{unique_id}\" ; supports placeholders
 
-    ; Access point settings
-    -D FACTORY_AP_PROVISION_MODE=AP_MODE_DISCONNECTED
-    -D FACTORY_AP_SSID=\"ESP8266-React\" ; 1-64 characters
-    -D FACTORY_AP_PASSWORD=\"esp-react\" ; 8-64 characters
-    -D FACTORY_AP_LOCAL_IP=\"192.168.4.1\"
-    -D FACTORY_AP_GATEWAY_IP=\"192.168.4.1\"
-    -D FACTORY_AP_SUBNET_MASK=\"255.255.255.0\"
+  ; Access point settings
+  -D FACTORY_AP_PROVISION_MODE=AP_MODE_DISCONNECTED
+  -D FACTORY_AP_SSID=\"ESP8266-React-#{unique_id}\" ; 1-64 characters, supports placeholders
+  -D FACTORY_AP_PASSWORD=\"esp-react\" ; 8-64 characters
+  -D FACTORY_AP_LOCAL_IP=\"192.168.4.1\"
+  -D FACTORY_AP_GATEWAY_IP=\"192.168.4.1\"
+  -D FACTORY_AP_SUBNET_MASK=\"255.255.255.0\"
 
-    ; User credentials for admin and guest user
-    -D FACTORY_ADMIN_USERNAME=\"admin\"
-    -D FACTORY_ADMIN_PASSWORD=\"admin\"
-    -D FACTORY_GUEST_USERNAME=\"guest\"
-    -D FACTORY_GUEST_PASSWORD=\"guest\"
+  ; User credentials for admin and guest user
+  -D FACTORY_ADMIN_USERNAME=\"admin\"
+  -D FACTORY_ADMIN_PASSWORD=\"admin\"
+  -D FACTORY_GUEST_USERNAME=\"guest\"
+  -D FACTORY_GUEST_PASSWORD=\"guest\"
 
-    ; NTP settings
-    -D FACTORY_NTP_ENABLED=true
-    -D FACTORY_NTP_TIME_ZONE_LABEL=\"Europe/London\"
-    -D FACTORY_NTP_TIME_ZONE_FORMAT=\"GMT0BST,M3.5.0/1,M10.5.0\"
-    -D FACTORY_NTP_SERVER=\"time.google.com\"
+  ; NTP settings
+  -D FACTORY_NTP_ENABLED=true
+  -D FACTORY_NTP_TIME_ZONE_LABEL=\"Europe/London\"
+  -D FACTORY_NTP_TIME_ZONE_FORMAT=\"GMT0BST,M3.5.0/1,M10.5.0\"
+  -D FACTORY_NTP_SERVER=\"time.google.com\"
 
-    ; OTA settings
-    -D FACTORY_OTA_PORT=8266
-    -D FACTORY_OTA_PASSWORD=\"esp-react\"
-    -D FACTORY_OTA_ENABLED=true
+  ; OTA settings
+  -D FACTORY_OTA_PORT=8266
+  -D FACTORY_OTA_PASSWORD=\"esp-react\"
+  -D FACTORY_OTA_ENABLED=true
 
-    ; MQTT settings
-    -D FACTORY_MQTT_ENABLED=false
-    -D FACTORY_MQTT_HOST=\"test.mosquitto.org\"
-    -D FACTORY_MQTT_PORT=1883
-    -D FACTORY_MQTT_USERNAME=\"\"
-    -D FACTORY_MQTT_PASSWORD=\"\"
-    ; if unspecified the devices hardware ID will be used
-    ;-D FACTORY_MQTT_CLIENT_ID=\"esp-react\"
-    -D FACTORY_MQTT_KEEP_ALIVE=60
-    -D FACTORY_MQTT_CLEAN_SESSION=true
-    -D FACTORY_MQTT_MAX_TOPIC_LENGTH=128
+  ; MQTT settings
+  -D FACTORY_MQTT_ENABLED=false
+  -D FACTORY_MQTT_HOST=\"test.mosquitto.org\"
+  -D FACTORY_MQTT_PORT=1883
+  -D FACTORY_MQTT_USERNAME=\"\" ; supports placeholders
+  -D FACTORY_MQTT_PASSWORD=\"\"
+  -D FACTORY_MQTT_CLIENT_ID=\"#{platform}-#{unique_id}\" ; supports placeholders
+  -D FACTORY_MQTT_KEEP_ALIVE=60
+  -D FACTORY_MQTT_CLEAN_SESSION=true
+  -D FACTORY_MQTT_MAX_TOPIC_LENGTH=128
 
-    ; JWT Secret
-    ; if unspecified the devices hardware ID will be used
-    ; -D FACTORY_JWT_SECRET=\"esp8266-react\"
+  ; JWT Secret
+  -D FACTORY_JWT_SECRET=\"#{random}-#{random}\" ; supports placeholders
diff --git a/features.ini b/features.ini
index f68b0ae..ffb890d 100644
--- a/features.ini
+++ b/features.ini
@@ -1,8 +1,8 @@
 [features]
 build_flags = 
-    -D FT_PROJECT=1
-    -D FT_SECURITY=1
-    -D FT_MQTT=1
-    -D FT_NTP=1
-    -D FT_OTA=1
-    -D FT_UPLOAD_FIRMWARE=1
+  -D FT_PROJECT=1
+  -D FT_SECURITY=1
+  -D FT_MQTT=1
+  -D FT_NTP=1
+  -D FT_OTA=1
+  -D FT_UPLOAD_FIRMWARE=1
diff --git a/lib/framework/APSettingsService.h b/lib/framework/APSettingsService.h
index 9104615..896d96a 100644
--- a/lib/framework/APSettingsService.h
+++ b/lib/framework/APSettingsService.h
@@ -1,6 +1,7 @@
 #ifndef APSettingsConfig_h
 #define APSettingsConfig_h
 
+#include <SettingValue.h>
 #include <HttpEndpoint.h>
 #include <FSPersistence.h>
 #include <JsonUtils.h>
@@ -8,20 +9,12 @@
 #include <DNSServer.h>
 #include <IPAddress.h>
 
-#define MANAGE_NETWORK_DELAY 10000
-
-#define AP_MODE_ALWAYS 0
-#define AP_MODE_DISCONNECTED 1
-#define AP_MODE_NEVER 2
-
-#define DNS_PORT 53
-
 #ifndef FACTORY_AP_PROVISION_MODE
 #define FACTORY_AP_PROVISION_MODE AP_MODE_DISCONNECTED
 #endif
 
 #ifndef FACTORY_AP_SSID
-#define FACTORY_AP_SSID "ESP8266-React"
+#define FACTORY_AP_SSID "ESP8266-React-#{unique_id}"
 #endif
 
 #ifndef FACTORY_AP_PASSWORD
@@ -43,6 +36,14 @@
 #define AP_SETTINGS_FILE "/config/apSettings.json"
 #define AP_SETTINGS_SERVICE_PATH "/rest/apSettings"
 
+#define MANAGE_NETWORK_DELAY 10000
+
+#define AP_MODE_ALWAYS 0
+#define AP_MODE_DISCONNECTED 1
+#define AP_MODE_NEVER 2
+
+#define DNS_PORT 53
+
 enum APNetworkStatus { ACTIVE = 0, INACTIVE, LINGERING };
 
 class APSettings {
@@ -79,7 +80,7 @@ class APSettings {
       default:
         newSettings.provisionMode = AP_MODE_ALWAYS;
     }
-    newSettings.ssid = root["ssid"] | FACTORY_AP_SSID;
+    newSettings.ssid = root["ssid"] | SettingValue::format(FACTORY_AP_SSID);
     newSettings.password = root["password"] | FACTORY_AP_PASSWORD;
 
     JsonUtils::readIP(root, "local_ip", newSettings.localIP, FACTORY_AP_LOCAL_IP);
diff --git a/lib/framework/ESPUtils.h b/lib/framework/ESPUtils.h
deleted file mode 100644
index 834459d..0000000
--- a/lib/framework/ESPUtils.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#ifndef ESPUtils_h
-#define ESPUtils_h
-
-#include <Arduino.h>
-
-class ESPUtils {
- public:
-  static String defaultDeviceValue(String prefix = "") {
-#ifdef ESP32
-    return prefix + String((unsigned long)ESP.getEfuseMac(), HEX);
-#elif defined(ESP8266)
-    return prefix + String(ESP.getChipId(), HEX);
-#endif
-  }
-};
-
-#endif  // end ESPUtils
diff --git a/lib/framework/FSPersistence.h b/lib/framework/FSPersistence.h
index 9fc547b..f3d9573 100644
--- a/lib/framework/FSPersistence.h
+++ b/lib/framework/FSPersistence.h
@@ -38,9 +38,11 @@ class FSPersistence {
       settingsFile.close();
     }
 
-    // If we reach here we have not been successful in loading the config,
-    // hard-coded emergency defaults are now applied.
+    // If we reach here we have not been successful in loading the config and hard-coded defaults are now applied.
+    // The settings are then written back to the file system so the defaults persist between resets. This last step is
+    // required as in some cases defaults contain randomly generated values which would otherwise be modified on reset.
     applyDefaults();
+    writeToFS();
   }
 
   bool writeToFS() {
diff --git a/lib/framework/MqttSettingsService.h b/lib/framework/MqttSettingsService.h
index e6a0357..a011743 100644
--- a/lib/framework/MqttSettingsService.h
+++ b/lib/framework/MqttSettingsService.h
@@ -5,12 +5,7 @@
 #include <HttpEndpoint.h>
 #include <FSPersistence.h>
 #include <AsyncMqttClient.h>
-#include <ESPUtils.h>
-
-#define MQTT_RECONNECTION_DELAY 5000
-
-#define MQTT_SETTINGS_FILE "/config/mqttSettings.json"
-#define MQTT_SETTINGS_SERVICE_PATH "/rest/mqttSettings"
+#include <SettingValue.h>
 
 #ifndef FACTORY_MQTT_ENABLED
 #define FACTORY_MQTT_ENABLED false
@@ -33,7 +28,7 @@
 #endif
 
 #ifndef FACTORY_MQTT_CLIENT_ID
-#define FACTORY_MQTT_CLIENT_ID generateClientId()
+#define FACTORY_MQTT_CLIENT_ID "#{platform}-#{unique_id}"
 #endif
 
 #ifndef FACTORY_MQTT_KEEP_ALIVE
@@ -48,13 +43,10 @@
 #define FACTORY_MQTT_MAX_TOPIC_LENGTH 128
 #endif
 
-static String generateClientId() {
-#ifdef ESP32
-  return ESPUtils::defaultDeviceValue("esp32-");
-#elif defined(ESP8266)
-  return ESPUtils::defaultDeviceValue("esp8266-");
-#endif
-}
+#define MQTT_SETTINGS_FILE "/config/mqttSettings.json"
+#define MQTT_SETTINGS_SERVICE_PATH "/rest/mqttSettings"
+
+#define MQTT_RECONNECTION_DELAY 5000
 
 class MqttSettings {
  public:
@@ -91,9 +83,9 @@ class MqttSettings {
     settings.enabled = root["enabled"] | FACTORY_MQTT_ENABLED;
     settings.host = root["host"] | FACTORY_MQTT_HOST;
     settings.port = root["port"] | FACTORY_MQTT_PORT;
-    settings.username = root["username"] | FACTORY_MQTT_USERNAME;
+    settings.username = root["username"] | SettingValue::format(FACTORY_MQTT_USERNAME);
     settings.password = root["password"] | FACTORY_MQTT_PASSWORD;
-    settings.clientId = root["client_id"] | FACTORY_MQTT_CLIENT_ID;
+    settings.clientId = root["client_id"] | SettingValue::format(FACTORY_MQTT_CLIENT_ID);
     settings.keepAlive = root["keep_alive"] | FACTORY_MQTT_KEEP_ALIVE;
     settings.cleanSession = root["clean_session"] | FACTORY_MQTT_CLEAN_SESSION;
     settings.maxTopicLength = root["max_topic_length"] | FACTORY_MQTT_MAX_TOPIC_LENGTH;
diff --git a/lib/framework/SecurityManager.h b/lib/framework/SecurityManager.h
index 530ab81..2302deb 100644
--- a/lib/framework/SecurityManager.h
+++ b/lib/framework/SecurityManager.h
@@ -4,14 +4,9 @@
 #include <Features.h>
 #include <ArduinoJsonJWT.h>
 #include <ESPAsyncWebServer.h>
-#include <ESPUtils.h>
 #include <AsyncJson.h>
 #include <list>
 
-#ifndef FACTORY_JWT_SECRET
-#define FACTORY_JWT_SECRET ESPUtils::defaultDeviceValue()
-#endif
-
 #define ACCESS_TOKEN_PARAMATER "access_token"
 
 #define AUTHORIZATION_HEADER "Authorization"
diff --git a/lib/framework/SecuritySettingsService.h b/lib/framework/SecuritySettingsService.h
index 236bfe4..c1a3f17 100644
--- a/lib/framework/SecuritySettingsService.h
+++ b/lib/framework/SecuritySettingsService.h
@@ -1,11 +1,16 @@
 #ifndef SecuritySettingsService_h
 #define SecuritySettingsService_h
 
+#include <SettingValue.h>
 #include <Features.h>
 #include <SecurityManager.h>
 #include <HttpEndpoint.h>
 #include <FSPersistence.h>
 
+#ifndef FACTORY_JWT_SECRET
+#define FACTORY_JWT_SECRET "#{random}-#{random}"
+#endif
+
 #ifndef FACTORY_ADMIN_USERNAME
 #define FACTORY_ADMIN_USERNAME "admin"
 #endif
@@ -48,7 +53,7 @@ class SecuritySettings {
 
   static StateUpdateResult update(JsonObject& root, SecuritySettings& settings) {
     // secret
-    settings.jwtSecret = root["jwt_secret"] | FACTORY_JWT_SECRET;
+    settings.jwtSecret = root["jwt_secret"] | SettingValue::format(FACTORY_JWT_SECRET);
 
     // users
     settings.users.clear();
@@ -103,7 +108,7 @@ class SecuritySettingsService : public SecurityManager {
   SecuritySettingsService(AsyncWebServer* server, FS* fs);
   ~SecuritySettingsService();
 
-  // minimal set of functions to support framework with security settings disabled  
+  // minimal set of functions to support framework with security settings disabled
   Authentication authenticateRequest(AsyncWebServerRequest* request);
   ArRequestFilterFunction filterRequest(AuthenticationPredicate predicate);
   ArRequestHandlerFunction wrapRequest(ArRequestHandlerFunction onRequest, AuthenticationPredicate predicate);
diff --git a/lib/framework/SettingValue.cpp b/lib/framework/SettingValue.cpp
new file mode 100644
index 0000000..c12e1b0
--- /dev/null
+++ b/lib/framework/SettingValue.cpp
@@ -0,0 +1,55 @@
+#include <SettingValue.h>
+
+namespace SettingValue {
+
+#ifdef ESP32
+const String PLATFORM = "esp32";
+#elif defined(ESP8266)
+const String PLATFORM = "esp8266";
+#endif
+
+/**
+ * Returns a new string after replacing each instance of the pattern with a value generated by calling the provided
+ * callback.
+ */
+String replaceEach(String value, String pattern, String (*generateReplacement)()) {
+  while (true) {
+    int index = value.indexOf(pattern);
+    if (index == -1) {
+      break;
+    }
+    value = value.substring(0, index) + generateReplacement() + value.substring(index + pattern.length());
+  }
+  return value;
+}
+
+/**
+ * Generates a random number, encoded as a hex string.
+ */
+String getRandom() {
+  return String(random(2147483647), HEX);
+}
+
+/**
+ * Uses the station's MAC address to create a unique id for each device.
+ */
+String getUniqueId() {
+  uint8_t mac[6];
+#ifdef ESP32
+  esp_read_mac(mac, ESP_MAC_WIFI_STA);
+#elif defined(ESP8266)
+  wifi_get_macaddr(STATION_IF, mac);
+#endif
+  char macStr[13] = {0};
+  sprintf(macStr, "%02x%02x%02x%02x%02x%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+  return String(macStr);
+}
+
+String format(String value) {
+  value = replaceEach(value, "#{random}", getRandom);
+  value.replace("#{unique_id}", getUniqueId());
+  value.replace("#{platform}", PLATFORM);
+  return value;
+}
+
+};  // end namespace SettingValue
diff --git a/lib/framework/SettingValue.h b/lib/framework/SettingValue.h
new file mode 100644
index 0000000..cc5e0e3
--- /dev/null
+++ b/lib/framework/SettingValue.h
@@ -0,0 +1,14 @@
+#ifndef SettingValue_h
+#define SettingValue_h
+
+#include <Arduino.h>
+
+#ifdef ESP8266
+#include <ESP8266WiFi.h>
+#endif
+
+namespace SettingValue {
+String format(String value);
+};
+
+#endif  // end SettingValue
diff --git a/lib/framework/WiFiSettingsService.h b/lib/framework/WiFiSettingsService.h
index 2b520bd..3d1dc22 100644
--- a/lib/framework/WiFiSettingsService.h
+++ b/lib/framework/WiFiSettingsService.h
@@ -1,15 +1,12 @@
 #ifndef WiFiSettingsService_h
 #define WiFiSettingsService_h
 
+#include <SettingValue.h>
 #include <StatefulService.h>
 #include <FSPersistence.h>
 #include <HttpEndpoint.h>
 #include <JsonUtils.h>
 
-#define WIFI_SETTINGS_FILE "/config/wifiSettings.json"
-#define WIFI_SETTINGS_SERVICE_PATH "/rest/wifiSettings"
-#define WIFI_RECONNECTION_DELAY 1000 * 30
-
 #ifndef FACTORY_WIFI_SSID
 #define FACTORY_WIFI_SSID ""
 #endif
@@ -19,9 +16,14 @@
 #endif
 
 #ifndef FACTORY_WIFI_HOSTNAME
-#define FACTORY_WIFI_HOSTNAME ESPUtils::defaultDeviceValue("esp-react-")
+#define FACTORY_WIFI_HOSTNAME "#{platform}-#{unique_id}"
 #endif
 
+#define WIFI_SETTINGS_FILE "/config/wifiSettings.json"
+#define WIFI_SETTINGS_SERVICE_PATH "/rest/wifiSettings"
+
+#define WIFI_RECONNECTION_DELAY 1000 * 30
+
 class WiFiSettings {
  public:
   // core wifi configuration
@@ -55,7 +57,7 @@ class WiFiSettings {
   static StateUpdateResult update(JsonObject& root, WiFiSettings& settings) {
     settings.ssid = root["ssid"] | FACTORY_WIFI_SSID;
     settings.password = root["password"] | FACTORY_WIFI_PASSWORD;
-    settings.hostname = root["hostname"] | FACTORY_WIFI_HOSTNAME;
+    settings.hostname = root["hostname"] | SettingValue::format(FACTORY_WIFI_HOSTNAME);
     settings.staticIPConfig = root["static_ip_config"] | false;
 
     // extended settings
diff --git a/src/LightMqttSettingsService.h b/src/LightMqttSettingsService.h
index 23a2218..e7b66b0 100644
--- a/src/LightMqttSettingsService.h
+++ b/src/LightMqttSettingsService.h
@@ -3,7 +3,7 @@
 
 #include <HttpEndpoint.h>
 #include <FSPersistence.h>
-#include <ESPUtils.h>
+#include <SettingValue.h>
 
 #define LIGHT_BROKER_SETTINGS_FILE "/config/brokerSettings.json"
 #define LIGHT_BROKER_SETTINGS_PATH "/rest/brokerSettings"
@@ -21,9 +21,9 @@ class LightMqttSettings {
   }
 
   static StateUpdateResult update(JsonObject& root, LightMqttSettings& settings) {
-    settings.mqttPath = root["mqtt_path"] | ESPUtils::defaultDeviceValue("homeassistant/light/");
-    settings.name = root["name"] | ESPUtils::defaultDeviceValue("light-");
-    settings.uniqueId = root["unique_id"] | ESPUtils::defaultDeviceValue("light-");
+    settings.mqttPath = root["mqtt_path"] | SettingValue::format("homeassistant/light/#{unique_id}");
+    settings.name = root["name"] | SettingValue::format("light-#{unique_id}");
+    settings.uniqueId = root["unique_id"] | SettingValue::format("light-#{unique_id}");
     return StateUpdateResult::CHANGED;
   }
 };