I don’t think there is a point in using keyring if you don’t want to save multiple passwords in the same qube. You need to enter the keyring password to decrypt the keyring storage every time you start the qube, then why not just enter the password to the website/app/etc directly instead of saving it in the keyring.
Also the passwords in the keyring are only protected when the keyring is locked so it’s a protection from something like your qubes storage being leaked (e.g. your backup+backup password). So it’s a very rare case.