Hiding placeholder blocks from published content

Hi there,

I have a use case that I don't think is covered by the product as it currently exists.

I work on creating training materials for software solutions that change rapidly. This means that I can be writing a module in the knowledge that in the pipeline are updates that will fundamentally affect the flow of the lesson. 

I want to be able to add placeholders for future features, but elect to hide them so that they do not display in a published output. (Similar to hidden slides in a Powerpoint deck that don't display during a presentation in presenter mode.)