Actually, yes: they have the same endpoint via Kubernetes’ Service, but in the case of Master — an…

Actually, yes: they have the same endpoint via Kubernetes’ Service, but in the case of Master — an application has to ask for Sentinel about the current Master node and then send a request to it.
But, again, as I outlined on the post — even when you’ll send a WRITE request — it somehow will be pointed exactly to a Master host, even without asking a Sentinel instance first.