Currently if you want to make an encrypted export of your vault (not account bound) using your master password as the key, you will have to type in your master password twice to choose and confirm the password; then you must type your master password in to confirm the export. It would be nice if there was an option to use your master password so that you only have to type it in twice (or once) rather than 3 times. I am unaware of any security issues with using the master password as the key for the export.
You may be interested in this discussion from another recent thread:
That does make sense. I suppose they shouldn’t encourage doing so with the feature I am requesting. I currently only use the future to download the vault securely which then goes into my actual backup with a different password.