Since extra addresses can be an optional feature, users can opt-in and opt-out at any moment. I said above: Permanent or Default; it is permanent because this address does not change at least you manually pick another address to be your permanent one. Default, because this address is the one that it will be listening whether you have the feature enabled or not. Since you can disable the feature, the last permanent address will be your default address.
What is the difference between one-time address and reusable then?
Disposable means that I can not use that address after completing the receiving process because it is a one-time use address. Reusable means that I can use this address at any moment. For example, If I am mining in two different pools, I can create two address, one for one pool and one for another pool.
Let’s say I don’t want to share my default address and I’m not mining, in this case I can create disposable addresses for each transaction. Or maybe I’m currently receiving payments on my default address (m/0/0/0) but I want to start using disposable addresses, I just need to enable the feature and that’s all.
Also, I could change my default address without using extra addresses.
I asked explicitly about the flow of a manual confirmation just to make sure I’m not missing any step. For a manual confirmation, the transaction is not “received” until you accept it. In this case, a disposable address won’t expire until you accept the transaction.
Now… if you want to go only with a manual confirmation flow, maybe you will need to be able of having multiple extra addresses listening at the same time in order to receive multiple transaction using different address which are not your default one. In other words: you may want to enable different addresses at the same time besides the default one.
Your screen may look like this then:
Let me know if I’m understanding your point of view please @vegycslol