Currently only Beats and Blocks and Groups are visible in White Board. But I often need a memo, reminder, signpost, or label on the White Board—not a Beat, Block, Group—something pinned to the timeline. Really, a Post-It is the perfect metaphor.
Right now I do that with empty Blocks, but though these maintain their position relative to other elements, they unfortunately look just like proper Blocks and are very limited in their appearance. Even if I change their colors and give them more descriptive names, they fall short (they are limited to one expanding line of text).