I would love the ability to leave comments within an affinity designer document! It would be nice if there was a comment panel, similar to the history panel, that had a list of all the comments that have been left on the document. Then, when you click on one of those comments, it highlights and shows the location of where the comment was left within the document. And to leave comments, if there was a "comment" tool we could just click different places within the document, and leave a comment there. Also, it would be nice to show/hide all comments at once.