diff --git a/docs/proposals/component-definition.zh.md b/docs/proposals/component-definition.zh.md
index bbd1ed7..0fe59e6 100644
--- a/docs/proposals/component-definition.zh.md
+++ b/docs/proposals/component-definition.zh.md
@@ -479,8 +479,9 @@ attrs 遵守下面的不变量：
 - `class` 合并并去重；
 - Ebox style/layout attrs 先按 canonical property domain 去重，调用方值覆盖组件视觉
   默认值；
-- `role`、`ref`、`disabled`、`:on-*` 等 Runtime metadata 若与根 Host 已有值冲突，
-  精确报错；需要由 Component 管理的 metadata 应声明为业务 prop；
+- `role`、`ref`、`disabled`、`:on-*` 等 Runtime metadata 与普通前端 attrs 一样由
+  调用方覆盖根默认值；必须由 Component 掌控的 metadata 应显式声明为业务 prop，
+  从 attrs 域中消费；
 - attrs 在调用方 Component 环境中求值，不能泄漏到被调用 Component 的 setup、
   `etaf-state` 或业务 props；
 - 实际根 Host 仍通过 `ebox-style-property-accepted-p` 验证适用域，例如 Text 根不能
diff --git a/etaf-renderer.el b/etaf-renderer.el
index e6717df..24f1d4a 100644
--- a/etaf-renderer.el
+++ b/etaf-renderer.el
@@ -144,10 +144,14 @@ SITE-TOKEN replaces PATH as the generated call-site identity when non-nil."
   (or (plist-get props :ref)
       (let ((site (or site-token (copy-sequence path))))
         (list 'etaf-host
-              (if etaf--rendering-range-p
+              (cond
+               (etaf--rendering-range-p
                   (list :range etaf--current-semantic-parent-id
-                        :site site)
-                site)))))
+                        :site site))
+               (etaf--render-runtime
+                (list :parent etaf--current-semantic-parent-id :site site))
+               (t
+                (list :path (copy-sequence path) :site site)))))))
 
 (defun etaf--merge-property (props key value)
   "Return PROPS with KEY set to VALUE, preserving the original order."
diff --git a/etaf-view.el b/etaf-view.el
index 1025ef2..b2437b7 100644
--- a/etaf-view.el
+++ b/etaf-view.el
@@ -287,9 +287,7 @@ Component semantics.  COMPONENT-NAME labels diagnostics."
                 (append (etaf--plist-remove-domain result key)
                         (list key value))))
          ((plist-member result key)
-          (etaf--component-error
-           "Component %S root metadata %S conflicts with fallthrough"
-           component-name key))
+          (setq result (etaf--plist-set result key value)))
          (t
           (setq result (append result (list key value)))))))
     result))
diff --git a/tests/etaf-component-frontends-tests.el b/tests/etaf-component-frontends-tests.el
index 46b09d9..79803c6 100644
--- a/tests/etaf-component-frontends-tests.el
+++ b/tests/etaf-component-frontends-tests.el
@@ -651,16 +651,31 @@
        `((" *etaf-g6b-attrs-fragment*"
           ,(etaf-view (etaf-test-g6b-attr-fragment :color "red")))
          (" *etaf-g6b-attrs-text*"
-          ,(etaf-view (etaf-test-g6b-attr-text :padding 1)))
-         (" *etaf-g6b-attrs-role*"
-          ,(etaf-view (etaf-test-g6b-attr-role :role 'navigation)))))
+          ,(etaf-view (etaf-test-g6b-attr-text :padding 1)))))
     (let ((buffer (car entry)))
       (unwind-protect
           (should-error (etaf-mount buffer (cadr entry))
                         :type 'etaf-component-call-error)
         (when-let* ((runtime (etaf-runtime-for-buffer buffer)))
           (etaf-unmount runtime))
-        (when-let* ((live (get-buffer buffer))) (kill-buffer live))))))
+        (when-let* ((live (get-buffer buffer))) (kill-buffer live)))))
+  (let ((buffer " *etaf-g6b-attrs-role*"))
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer
+           (etaf-view
+            (etaf-test-g6b-attr-role
+             :role 'navigation :ref 'g6b-attrs-role)))
+          (should
+           (eq 'navigation
+               (plist-get
+                (etaf-runtime-host-props-for
+                 (etaf-runtime-for-buffer buffer) 'g6b-attrs-role)
+                :role))))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer)))
+        (etaf-unmount runtime))
+      (when-let* ((live (get-buffer buffer))) (kill-buffer live)))))
 
 (ert-deftest etaf-component-host-attrs-rollback-root-shape-failure ()
   "A later multi-root result cannot publish or retire the previous root."
@@ -687,5 +702,22 @@
         (etaf-unmount runtime))
       (when-let* ((live (get-buffer buffer))) (kill-buffer live)))))
 
+(ert-deftest etaf-component-compiled-host-sites-are-instance-scoped ()
+  "Two instances of one compiled Component never share generated Host refs."
+  (let ((buffer " *etaf-g6b-instance-sites*"))
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer
+           (etaf-view
+            (column
+             (etaf-test-g6b-attr-leaf :key 'one :label "One")
+             (etaf-test-g6b-attr-leaf :key 'two :label "Two"))))
+          (should (string-match-p
+                   "One[[:space:]]+Two" (etaf-test-g6b--text buffer))))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer)))
+        (etaf-unmount runtime))
+      (when-let* ((live (get-buffer buffer))) (kill-buffer live)))))
+
 (provide 'etaf-component-frontends-tests)
 ;;; etaf-component-frontends-tests.el ends here