Also an option to create a link to the image as PNG/PDF but which requires authorization would be really cool. So that we can integrate up to date link in online documentation. The only requirements for the reader would be to connect to Lucid before reading the docs. This would avoid the need to publish publicly our work.

Hi Luc thanks for posting in the Lucidchart Community! Password protection is only available for publishing via a publish link this option is currently not available for embedded documents as described in the Help Center article linked in your post.

While it is possible to publish your document with password protection as a PDF or image (see screenshot) it is not possible to share them in those formats within Lucidchart. You can however create a shareable link for your document that only grants view-only access to other Lucidchart users after they log in. The article Collaborate and Share in our Help Center gives more details on sharing permissions and shareable links.

We're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. Would you mind adding your ideas to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration. Thanks!