diff --git a/app/models/llm_model.rb b/app/models/llm_model.rb
index 937c5373..7834d065 100644
--- a/app/models/llm_model.rb
+++ b/app/models/llm_model.rb
@@ -99,7 +99,7 @@ class LlmModel < ActiveRecord::Base
   end
 
   def identifier
-    "custom:#{id}"
+    "#{id}"
   end
 
   def toggle_companion_user
diff --git a/assets/javascripts/discourse/components/ai-spam.gjs b/assets/javascripts/discourse/components/ai-spam.gjs
index 068c715e..7f4464cf 100644
--- a/assets/javascripts/discourse/components/ai-spam.gjs
+++ b/assets/javascripts/discourse/components/ai-spam.gjs
@@ -90,7 +90,7 @@ export default class AiSpam extends Component {
     this.isEnabled = model.is_enabled;
 
     if (model.llm_id) {
-      this.selectedLLM = "custom:" + model.llm_id;
+      this.selectedLLM = model.llm_id;
     } else {
       if (this.availableLLMs.length) {
         this.selectedLLM = this.availableLLMs[0].id;
diff --git a/config/settings.yml b/config/settings.yml
index ff770181..432aafdc 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -16,7 +16,7 @@ discourse_ai:
     type: enum
     allow_any: false
     enum: "DiscourseAi::Configuration::LlmEnumerator"
-    validator: "DiscourseAi::Configuration::SimpleLlmValidator"
+    validator: "DiscourseAi::Configuration::LlmValidator"
 
   ai_sentiment_enabled:
     default: false
diff --git a/db/migrate/20250710173803_seed_ai_default_llm_model.rb b/db/migrate/20250710173803_seed_ai_default_llm_model.rb
index c9710613..b5d9a122 100644
--- a/db/migrate/20250710173803_seed_ai_default_llm_model.rb
+++ b/db/migrate/20250710173803_seed_ai_default_llm_model.rb
@@ -6,7 +6,7 @@ class SeedAiDefaultLlmModel < ActiveRecord::Migration[7.2]
     last_model_id = DB.query_single("SELECT id FROM llm_models ORDER BY id DESC LIMIT 1").first
 
     if last_model_id.present?
-      execute "UPDATE site_settings SET value = 'custom:#{last_model_id}' WHERE name = 'ai_default_llm_model' AND (value IS NULL OR value = '');"
+      execute "UPDATE site_settings SET value = '#{last_model_id}' WHERE name = 'ai_default_llm_model' AND (value IS NULL OR value = '');"
     end
   end
 
diff --git a/db/migrate/20250710181656_copy_ai_helper_model_to_persona_default.rb b/db/migrate/20250710181656_copy_ai_helper_model_to_persona_default.rb
index 0b4187b1..9657ea23 100644
--- a/db/migrate/20250710181656_copy_ai_helper_model_to_persona_default.rb
+++ b/db/migrate/20250710181656_copy_ai_helper_model_to_persona_default.rb
@@ -12,7 +12,7 @@ class CopyAiHelperModelToPersonaDefault < ActiveRecord::Migration[7.2]
       execute(<<~SQL)
         UPDATE ai_personas
         SET default_llm_id = #{model_id}
-        WHERE id IN (-18, -19, -20, -21, -22, -23, -24, -25, -26) AND default_llm_id IS NULL
+        WHERE id IN (-18, -19, -20, -21, -22, -23, -24, -25) AND default_llm_id IS NULL
       SQL
     end
   end
diff --git a/db/migrate/20250716005451_copy_translation_model_to_persona.rb b/db/migrate/20250716005451_copy_translation_model_to_persona.rb
new file mode 100644
index 00000000..478a6c46
--- /dev/null
+++ b/db/migrate/20250716005451_copy_translation_model_to_persona.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+class CopyTranslationModelToPersona < ActiveRecord::Migration[7.2]
+  def up
+    ai_translation_model =
+      DB.query_single("SELECT value FROM site_settings WHERE name = 'ai_translation_model'").first
+
+    if ai_translation_model.present? && ai_translation_model.start_with?("custom:")
+      # Extract the model ID from the setting value (e.g., "custom:-5" -> "-5")
+      model_id = ai_translation_model.split(":").last
+
+      # Update the translation personas (IDs -27, -28, -29, -30) with the extracted model ID
+      execute(<<~SQL)
+        UPDATE ai_personas
+        SET default_llm_id = #{model_id}
+        WHERE id IN (-27, -28, -29, -30) AND default_llm_id IS NULL
+      SQL
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end
diff --git a/db/migrate/20250716005855_copy_ai_image_caption_model_to_persona_default.rb b/db/migrate/20250716005855_copy_ai_image_caption_model_to_persona_default.rb
new file mode 100644
index 00000000..a797c1b3
--- /dev/null
+++ b/db/migrate/20250716005855_copy_ai_image_caption_model_to_persona_default.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+class CopyAiImageCaptionModelToPersonaDefault < ActiveRecord::Migration[7.2]
+  def up
+    ai_helper_image_caption_model =
+      DB.query_single(
+        "SELECT value FROM site_settings WHERE name = 'ai_helper_image_caption_model'",
+      ).first
+
+    if ai_helper_image_caption_model.present? &&
+         ai_helper_image_caption_model.start_with?("custom:")
+      # Extract the model ID from the setting value (e.g., "custom:1" -> "1")
+      model_id = ai_helper_image_caption_model.split(":").last
+
+      # Update the helper personas with the extracted model ID
+      execute(<<~SQL)
+        UPDATE ai_personas
+        SET default_llm_id = #{model_id}
+        WHERE id IN (-26) AND default_llm_id IS NULL
+      SQL
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end
diff --git a/lib/ai_helper/assistant.rb b/lib/ai_helper/assistant.rb
index 550a3362..01a27675 100644
--- a/lib/ai_helper/assistant.rb
+++ b/lib/ai_helper/assistant.rb
@@ -314,19 +314,11 @@ module DiscourseAi
       #   1. Persona's default LLM
       #   2. SiteSetting.ai_default_llm_id (or newest LLM if not set)
       def self.find_ai_helper_model(helper_mode, persona_klass)
-        model_id =
-          persona_klass.default_llm_id || SiteSetting.ai_default_llm_model&.split(":")&.last # Remove legacy custom provider.
+        model_id = persona_klass.default_llm_id || SiteSetting.ai_default_llm_model
 
         if model_id.present?
           LlmModel.find_by(id: model_id)
         else
-          last_model_id = LlmModel.last&.id
-
-          # SiteSetting.ai_default_llm_model shouldn't be empty, but if it is, we set it to the last model.
-          if last_model_id.present? && SiteSetting.ai_default_llm_model.empty?
-            SiteSetting.set_and_log("ai_default_llm_model", "custom:#{last_model_id}", Discourse.system_user) # Remove legacy custom provider.
-          end
-
           LlmModel.last
         end
       end
diff --git a/lib/configuration/llm_enumerator.rb b/lib/configuration/llm_enumerator.rb
index 200fc0a2..ac455c0a 100644
--- a/lib/configuration/llm_enumerator.rb
+++ b/lib/configuration/llm_enumerator.rb
@@ -5,6 +5,7 @@ require "enum_site_setting"
 module DiscourseAi
   module Configuration
     class LlmEnumerator < ::EnumSiteSetting
+      # TODO: global_usage is no longer accurate, it should be removed/updated
       def self.global_usage
         rval = Hash.new { |h, k| h[k] = [] }
 
@@ -107,7 +108,6 @@ module DiscourseAi
             end
         end
 
-        values.each { |value_h| value_h[:value] = "custom:#{value_h[:value]}" }
         values
       end
     end
diff --git a/lib/configuration/llm_validator.rb b/lib/configuration/llm_validator.rb
index 36c3c63b..7c985c5f 100644
--- a/lib/configuration/llm_validator.rb
+++ b/lib/configuration/llm_validator.rb
@@ -2,9 +2,6 @@
 
 module DiscourseAi
   module Configuration
-    class InvalidSeededModelError < StandardError
-    end
-
     class LlmValidator
       def initialize(opts = {})
         @opts = opts
@@ -18,12 +15,7 @@ module DiscourseAi
           return !@parent_enabled
         end
 
-        allowed_seeded_model?(val)
-
         run_test(val).tap { |result| @unreachable = result }
-      rescue DiscourseAi::Configuration::InvalidSeededModelError => e
-        @unreachable = true
-        false
       rescue StandardError => e
         raise e if Rails.env.test?
         @unreachable = true
@@ -31,6 +23,11 @@ module DiscourseAi
       end
 
       def run_test(val)
+        if Rails.env.test?
+          # In test mode, we assume the model is reachable.
+          return true
+        end
+
         DiscourseAi::Completions::Llm
           .proxy(val)
           .generate("How much is 1 + 1?", user: nil, feature_name: "llm_validator")
@@ -53,10 +50,6 @@ module DiscourseAi
           )
         end
 
-        if @invalid_seeded_model
-          return I18n.t("discourse_ai.llm.configuration.invalid_seeded_model")
-        end
-
         return unless @unreachable
 
         I18n.t("discourse_ai.llm.configuration.model_unreachable")
@@ -68,25 +61,12 @@ module DiscourseAi
 
       def modules_and_choose_llm_settings
         {
-          ai_embeddings_semantic_search_enabled: :ai_embeddings_semantic_search_hyde_model,
-          ai_helper_enabled: :ai_helper_model,
-          ai_summarization_enabled: :ai_summarization_model,
-          ai_translation_enabled: :ai_translation_model,
+          ai_embeddings_semantic_search_enabled: :ai_default_llm_model,
+          ai_helper_enabled: :ai_default_llm_model,
+          ai_summarization_enabled: :ai_default_llm_model,
+          ai_translation_enabled: :ai_default_llm_model,
         }
       end
-
-      def allowed_seeded_model?(val)
-        id = val.split(":").last
-        return true if id.to_i > 0
-
-        setting = @opts[:name]
-        allowed_list = SiteSetting.public_send("#{setting}_allowed_seeded_models")
-
-        if allowed_list.split("|").exclude?(id)
-          @invalid_seeded_model = true
-          raise DiscourseAi::Configuration::InvalidSeededModelError.new
-        end
-      end
     end
   end
 end
diff --git a/lib/configuration/simple_llm_validator.rb b/lib/configuration/simple_llm_validator.rb
deleted file mode 100644
index 301ac4ad..00000000
--- a/lib/configuration/simple_llm_validator.rb
+++ /dev/null
@@ -1,39 +0,0 @@
-# frozen_string_literal: true
-
-module DiscourseAi
-  module Configuration
-    class SimpleLlmValidator
-      def initialize(opts = {})
-        @opts = opts
-      end
-
-      def valid_value?(val)
-        return true if val == ""
-
-        run_test(val).tap { |result| @unreachable = result }
-      rescue StandardError => e
-        raise e if Rails.env.test?
-        @unreachable = true
-        true
-      end
-
-      def run_test(val)
-        if Rails.env.test?
-          # In test mode, we assume the model is reachable.
-          return true
-        end
-
-        DiscourseAi::Completions::Llm
-          .proxy(val)
-          .generate("How much is 1 + 1?", user: nil, feature_name: "llm_validator")
-          .present?
-      end
-
-      def error_message
-        return unless @unreachable
-
-        I18n.t("discourse_ai.llm.configuration.model_unreachable")
-      end
-    end
-  end
-end
diff --git a/lib/embeddings/semantic_search.rb b/lib/embeddings/semantic_search.rb
index a1c0b01e..e4e894ca 100644
--- a/lib/embeddings/semantic_search.rb
+++ b/lib/embeddings/semantic_search.rb
@@ -212,22 +212,13 @@ module DiscourseAi
       #   1. Persona's default LLM
       #   2. SiteSetting.ai_default_llm_id (or newest LLM if not set)
       def find_ai_hyde_model(persona_klass)
-        model_id =
-          persona_klass.default_llm_id || SiteSetting.ai_default_llm_model&.split(":")&.last # Remove legacy custom provider.
+        model_id = persona_klass.default_llm_id || SiteSetting.ai_default_llm_model
 
         if model_id.present?
           LlmModel.find_by(id: model_id)
         else
-          last_model_id = LlmModel.last&.id
-
-          # SiteSetting.ai_default_llm_model shouldn't be empty, but if it is, we set it to the last model.
-          if last_model_id.present? && SiteSetting.ai_default_llm_model.empty?
-            SiteSetting.set_and_log("ai_default_llm_model", "custom:#{last_model_id}", Discourse.system_user) # Remove legacy custom provider.
-          end
-
           LlmModel.last
         end
-
       end
 
       private
diff --git a/lib/summarization.rb b/lib/summarization.rb
index e4706cbd..f8f71cab 100644
--- a/lib/summarization.rb
+++ b/lib/summarization.rb
@@ -56,19 +56,11 @@ module DiscourseAi
       #   1. Persona's default LLM
       #   2. SiteSetting.ai_default_llm_id (or newest LLM if not set)
       def find_summarization_model(persona_klass)
-        model_id =
-          persona_klass.default_llm_id || SiteSetting.ai_default_llm_model&.split(":")&.last # Remove legacy custom provider.
+        model_id = persona_klass.default_llm_id || SiteSetting.ai_default_llm_model
 
         if model_id.present?
           LlmModel.find_by(id: model_id)
         else
-          last_model_id = LlmModel.last&.id
-
-          # SiteSetting.ai_default_llm_model shouldn't be empty, but if it is, we set it to the last model.
-          if last_model_id.present? && SiteSetting.ai_default_llm_model.empty?
-            SiteSetting.set_and_log("ai_default_llm_model", "custom:#{last_model_id}", Discourse.system_user) # Remove legacy custom provider.
-          end
-
           LlmModel.last
         end
       end
@@ -79,7 +71,7 @@ module DiscourseAi
         persona = persona_klass.new
         user = User.find_by(id: persona_klass.user_id) || Discourse.system_user
 
-        bot = DiscourseAi::Personas::Bot.as(user, persona: persona, model: llm_model)
+        DiscourseAi::Personas::Bot.as(user, persona: persona, model: llm_model)
       end
     end
   end
diff --git a/lib/translation/base_translator.rb b/lib/translation/base_translator.rb
index 2777c873..24749ac2 100644
--- a/lib/translation/base_translator.rb
+++ b/lib/translation/base_translator.rb
@@ -60,9 +60,13 @@ module DiscourseAi
       end
 
       def self.preferred_llm_model(persona_klass)
-        id = persona_klass.default_llm_id || SiteSetting.ai_translation_model&.split(":")&.last
-        return nil if id.blank?
-        LlmModel.find_by(id:)
+        model_id = persona_klass.default_llm_id || SiteSetting.ai_default_llm_model
+
+        if model_id.present?
+          LlmModel.find_by(id: model_id)
+        else
+          LlmModel.last
+        end
       end
     end
   end