Durable Subscription checkbox when checked serves two purposes
1. In an IME (Intermediate Message Event) if there are messages prior to the token reaching the IME they are delivered to the IME when the IME step is reached, without the checkbox selected the previous messages will be discarded.
2. In case of a server failure or restart the messages will still be delivered to the listener.
Related to this consume message flag simply means that the message will be consumed by the receiver and will not be available to other listeners with the same correlation.