Yes, you can use it permanently or reuse it, your coins will appear on your dashboard even though you will use different unused wallet addresses.

I tend to agree with all comments above, blockhain.com wallet has the worst services and if you have time to research it here, there are a lot of issues regarding their services.  Electrum is a good alternative Bitcoin wallet address and it has also an unused Bitcoin address that you may use too after making a transaction, it will generate a new address on its own.

If you didn't receive it yet, I think it's good if you will change to a new Bitcoin wallet platform that completely open-source code which is a noncustodial wallet.  You can download it here https://electrum.org/#download and don't forget to verify.