fix(docs,coap): Point out gap in ACE/new-workflow story

book/src/tooling/coap.md

@@ -233,4 +233,10 @@ to accept requests from newly created RIOT-rs based CoAP clients
 without the need for the CoAP client to create a network connection to the host.
 (Instead, the host needs to find the Resource Server over the network).
 
+.. note: Some more exploration of this workflow will be necessary
+  as to how the client can trigger the AS to re-install (or renew) its token
+  in case the Resource Server retired the token before its expiration.
+  For RIOT-rs internal use,
+  AS-provisioned tokens might just be retained longer.
+
 [New ACE Workflow developed in ACE]: https://www.ietf.org/archive/id/draft-ietf-ace-workflow-and-params-00.html#name-new-ace-workflow