Mark URLS as done when you fix them
You added a mark as done feature, but it seems to apply to finishing all of the items that had problems, not the individual urls as you fix them. Being able to mark the individual URLS as you fix them, or being able to delete them is what's really needed. Otherwise as you go through the list - say of pages with no organic traffic - and look at and fix a few urls one day, then go back the next day, it's hard to remember where you left off. Image below is an example of the level that mark as done would be helpful. (the drop down could have a mark as done option for the individual url to take it off the list or color it differently or something.