Use the push channel for speed and a scheduled poll for proof. Registered webhooks carry a revocation from the issuer to your gateway in a couple of seconds; scheduled polling is what tells you, an hour later, whether that revocation actually landed. On a support desk product where every tenant holds its own scoped key, the axis that decides the architecture is not median latency — it's whether you can reconstruct, for one key on one afternoon, when access stopped and how you learned about it. ...