When adding dependencies between tasks, it's impossible to differentiate between different tasks that have the same name. My team's account is set up with each project broken down into months of the year as milestones, and then subtasks under each milestone of the work that needs to be completed each month.
Sometimes, the same task needs to be completed in several different months, and so there will be two or more tasks of the same name that are nested under different milestones. Currently there's no way of telling which milestone which task belongs to when you try to add a dependency. Selecting the wrong one means that the wrong task gets auto-rescheduled to the wrong date, and you have to go back and amend it - it's a pain.
Displaying a breadcrumb under the task name would resolve this issue.
Breadcrumbs are displayed when adding dependencies between milestones, so hopefully it wouldn't be too much to extend this functionality to tasks/subtasks also.