You can give comments to tasks and projects in project manager which will show up in a long list of comments, which may or may not be related to each other. Additionally log entries for tasks show up in the general comments section, thereby mixing topics (hour logging and the comment with the comments e.g. by clients).
As an alternative I thought about pushing forums instead. So instead of writing a new comment, you would write a new posting with the option to "categorize" by e.g. starting a new topic. Additionally log entries would be fed into one new thread in the forum.
Each community / customer would have one forum instance. Each project would have one forum. Each task would have one thread in the project's forum, with the context_id of the task. I would add a parameter context_id to the forums-view to allow you to only view the threads with a specific task. All logging would be done in one additional thread.
This would effectively clean up the project view, as you are seeing the threads for the project (as well as comments on tasks, if there are any). Furthermore, you would have one long list of hour commits for a project along with the comments. On the other hand, this "problem" could be taken care of if you would just use logger and not post the logger comments into the task / project comments, but automatically send the comment to those subscribed to hour logging.