If I submit a family PDF document, but want to add a chapter later, how do I do that? Remove the original document and replace it with a new one? Or just open the document and edit it?
I believe - from past experience - you would need to do as you indicate - delete the current one and replace it with the new one (if under the filesize limitation) OR make the name/title indicate which chapter it is so that it can easily be viewed sequentially in Memories. For example, You could name the document title - [Book title]:Chapter 1, [Book title]:Chapter 2, etc.
Likely you will run into the filesize limitation at some point if you are publishing documents with multiple chapters...
I have journals that I upload as documents, and they often have many people tagged in them. Whenever I notice a typo or need to make some other update to the journal, I need to first write down all of the people who are tagged in it so I can re-tag them after I delete the journal and upload the update. It would be nice if a feature were added to allow a document to be updated, so this step of writing down who is tagged in it and then re-tagging them wouldn't be necessary.
You might wish to put your idea, with your explanation, in the "Suggest an Idea" section found to the right of this post. The engineers may be able to make it possible to update documents if the future.