If you are selecting a comment, the pin will have a small way of highlighting (whether it be a small square, yellow highlighter, red strikethrough or blue strikethrough) and will fit page to screen. This can be difficult to see when there are a lot of comments on one page. It would be helpful for it to center and zoom into the comment by 50% when selecting it.

Another recommendation: When I tag a reviewer, they get the email about my tag. However, when they go to find this tag, they have to scroll through every comment to find it. It would be great if it could show up at the top. I believe this can happen, since the reviewers have to make an account to review a document.