I would also like to know more about whether this functionality already exists or whether it will be implemented in the future. I feel it's quite an important one.
I'm currently trying to build a concept of a website / online network that I've been working on for some time. One example of needing this functionality is on my Directory pages (listing different businesses). Some businesses have websites, and others don't.
So if one page has a button linking to their website, there may be another that doesn't need one. For the time being I have found a workaround of applying styling directly to the dynamic element (so in the back-end, I have a form for 'website link' and another for 'website button title'). The website button title determines the text on the button.
If the fields are left empty, it simply won't display on that template page - if that makes sense?
However, I don't think that's going to work in your case, adioseven. Let me know if you've found a way to do that!