Currently, it’s only possible to password-protect Publishing via URL -- not PDFs.
This means any PDF sharing link is theoretically accessible to hackers if they were to spam the millions of possible links. Yes, it’s extremely unlikely for a hacker to guess the unprotected Lucid link as there are so many possible combinations, but it IS possible. Therefore, I cannot publish to PDF for my customers until this feature is added.
Work-around I would accept: being able to download as PDF from the password-protected URL WITHOUT having a Lucid account (currently, clicking “download as” redirects a user to sign up for a Lucid account...this is silly considering that PDF download is available for non-licensed users, BUT ONLY with an unprotected link as mentioned above, which is arguably unsecure)