diff --git a/applet/src/main/java/com/dangerousthings/aliro/AliroApplet.java b/applet/src/main/java/com/dangerousthings/aliro/AliroApplet.java
index 988e6e0..0d686af 100644
--- a/applet/src/main/java/com/dangerousthings/aliro/AliroApplet.java
+++ b/applet/src/main/java/com/dangerousthings/aliro/AliroApplet.java
@@ -880,10 +880,11 @@ public class AliroApplet extends Applet {
         // Aliro.a errors out when bits 0 + 2 are clear and AD is provisioned
         // -- it expects "AD present" to be advertised. The bits are
         // informational about capabilities anyway, not enforceable
-        // commitments, so 0x0005 satisfies the vendor library while we still
-        // 6D00 / 9000-stub any EXCHANGE/ENVELOPE that actually arrives.
-        // Revisit when real Step-up lands or when we test against more
-        // readers and can lean on the spec literally.
+        // commitments, so 0x0005 satisfies the vendor library. AliroApplet
+        // now returns 6D00 for any post-AUTH1 INS like 0xC9 -- StepUpApplet
+        // at ACCE5502 handles ENVELOPE and EXCHANGE properly per spec §10.2
+        // + §8.4. Revisit when we test against more readers and can lean on
+        // the spec literally.
         short bitmap = 0;
         if (store.hasAccessDocument()) {
             bitmap |= 0x0001;  // bit 0
diff --git a/applet/src/main/java/com/dangerousthings/aliro/StepUpApplet.java b/applet/src/main/java/com/dangerousthings/aliro/StepUpApplet.java
index 2f993ac..69dc6e7 100644
--- a/applet/src/main/java/com/dangerousthings/aliro/StepUpApplet.java
+++ b/applet/src/main/java/com/dangerousthings/aliro/StepUpApplet.java
@@ -53,11 +53,10 @@ import javacard.framework.Util;
  *       implantable target but document the limitation.</li>
  * </ol>
  *
- * <p>Also when this lands, revisit {@link AliroApplet}'s {@code INS_EXCHANGE}
- * stub: with real Step-Up at this AID, the stub becomes either (a) unused
- * if {@code signaling_bitmap} bit 2 stays set and spec-conformant readers
- * route EXCHANGE here, or (b) replaceable with a proper "Reader Status
- * sub-event" reply if X-CUBE-ALIRO's vendor bug persists.
+ * <p>The {@code AliroApplet.INS_EXCHANGE} stub was retired once StepUpApplet
+ * landed handling for 0xC9 directly — spec-conformant readers (X-CUBE-ALIRO
+ * included, once the upstream crypto interop is right) route EXCHANGE here
+ * after the step-up AID SELECT per §10.2.
  */
 public class StepUpApplet extends Applet {