In a similar product I have used in the past, there was a helpful feature where a user could manually send an alert to other users - not only "all" users as per the current functionality, individual users could be selected - to call attention to a specific file(s). As a practical example, this feature is very useful when multiple reviews of a document were required, as it allowed the next person(s) in the review cycle to be alerted immediately when the document was ready for review.
What I’m proposing is not a “blast” out to all users with access to the folder. It is the ability to select only the user(s) that actually needs to know that a file requires action. It also would include a text file to so that instructions could be provided to the user receiving the alert. For example, "Please review and send me an email accepting this version".