diff --git a/src/cliproxy/config/thinking-config.ts b/src/cliproxy/config/thinking-config.ts
index e0cda2eb..36d8a382 100644
--- a/src/cliproxy/config/thinking-config.ts
+++ b/src/cliproxy/config/thinking-config.ts
@@ -152,13 +152,11 @@ export function applyThinkingConfig(
   }
   thinkingValue = validation.value;
 
-  // If validation says off, don't apply suffix
-  if (thinkingValue === 'off') {
-    return result;
-  }
+  // Track whether to apply to main model (skip if validation says off)
+  const applyToMainModel = thinkingValue !== 'off';
 
-  // Apply thinking suffix to main model
-  if (result.ANTHROPIC_MODEL) {
+  // Apply thinking suffix to main model (only if not off)
+  if (applyToMainModel && result.ANTHROPIC_MODEL) {
     result.ANTHROPIC_MODEL = applyThinkingSuffix(result.ANTHROPIC_MODEL, thinkingValue);
   }
 
diff --git a/src/cliproxy/executor/index.ts b/src/cliproxy/executor/index.ts
index 92b42f49..c5dbde93 100644
--- a/src/cliproxy/executor/index.ts
+++ b/src/cliproxy/executor/index.ts
@@ -124,15 +124,20 @@ export async function execClaudeWithCLIProxy(
 
   // 0a. Runtime backend/provider validation
   const backend: CLIProxyBackend = unifiedConfig.cliproxy?.backend ?? DEFAULT_BACKEND;
-  if (backend === 'original' && PLUS_ONLY_PROVIDERS.includes(provider)) {
-    console.error('');
-    console.error(fail(`${provider} requires CLIProxyAPIPlus backend`));
-    console.error('');
-    console.error('To use this provider, either:');
-    console.error('  1. Set `cliproxy.backend: plus` in ~/.ccs/config.yaml');
-    console.error('  2. Use --backend=plus flag: ccs ' + provider + ' --backend=plus');
-    console.error('');
-    throw new Error(`Provider ${provider} requires Plus backend`);
+
+  // Collect all providers to validate (default + composite tiers)
+  const allProviders = [provider, ...compositeProviders];
+  for (const p of allProviders) {
+    if (backend === 'original' && PLUS_ONLY_PROVIDERS.includes(p as CLIProxyProvider)) {
+      console.error('');
+      console.error(fail(`${p} requires CLIProxyAPIPlus backend`));
+      console.error('');
+      console.error('To use this provider, either:');
+      console.error('  1. Set `cliproxy.backend: plus` in ~/.ccs/config.yaml');
+      console.error('  2. Use --backend=plus flag: ccs ' + p + ' --backend=plus');
+      console.error('');
+      throw new Error(`Provider ${p} requires Plus backend`);
+    }
   }
 
   const cliproxyServerConfig = unifiedConfig.cliproxy_server;
diff --git a/src/commands/cliproxy/variant-subcommand.ts b/src/commands/cliproxy/variant-subcommand.ts
index ef0c3618..0c41ee3f 100644
--- a/src/commands/cliproxy/variant-subcommand.ts
+++ b/src/commands/cliproxy/variant-subcommand.ts
@@ -168,15 +168,6 @@ export async function handleCreate(
     process.exit(1);
   }
 
-  // Clean up old variant if --force is set
-  if (variantExists(name) && parsedArgs.force) {
-    const removeResult = removeVariant(name);
-    if (!removeResult.success) {
-      console.log(fail(`Cannot overwrite variant '${name}': ${removeResult.error}`));
-      process.exit(1);
-    }
-  }
-
   // Composite mode: select provider+model per tier
   if (parsedArgs.composite) {
     console.log(info('Composite variant — select provider and model for each tier'));