If an artwork routing is multi-page and has lots of comments, wading through dozens of comments packed onto the screen is difficult.
One problem: clicking on a comment brings up a line pointing to "the general vicinity" of markup when zoomed out, but even when zoomed in, sometimes it is pointing at "air" or some tiny marker. Once you click the marker, then highlights, drawn boxes, and more spring into being.
This is only made worse by high-resolution displays.
What would be nice is a behavior not unlike Acrobat:
Click on comment.
All the other numeric "tags" on the screen vanish.
All the markup associated with that comment appears.