Bug: Drafts cannot be previewed

The UI shows buttons for viewing a form in different places like the 'View form' link here:

or using the button with the eye icon on the form's detail page here:

The Problem is: if the form is a draft (not published), the links do not work and lead to a soft-error page:

In my opinion, even drafts should be accessible for preview via a signed or temporary link. Or the preview buttons should be hidden, if a form is a draft. But I would prefer the first option.