I am not sure I understand your use case.
If you are sending to a non-durable (which I assume is what you mean about “temporary”), then you are using non-persistent messages.
TTL and “full” are concepts associated with persistent messages that get stored in a queue (or in the case of durable topics, Durable Topic Endpoints in PubSub+).
So for non-persistent messages, there is no storage of the messages and therefore no ability to have the queue be full. If there is no subscriber to the topic active, the messages just disappear.