I wish I was more of a Photoshop kind of a guy.
ALL I want is a semi-transparent vertical rule running from the top track to the bottom at every marker.
One VERY easy way to do this would be as follows.
Whatever colour I make a marker, the vertical rule at that point would take on that same colour. Get it? That would make it sooooo much easier to find my way through large projects.
This could be a .0x improvement.