Just my plus one too, its annoying. If you have 20 tasks in a day, you complete them all, end of the day you have a real big row in the timeline, so its annoying. BUT… it only clutters my view when tasks overlap, and so go onto mulitiple lines. Because we only use our timeline for our main “Project Planning Board” which are large development projects (tasks for projects) and not loads of small tasks that can be done in a day, we dont get a cluttered view much.
Do you need a timeline for all your small tasks that are done in a day? I would say no. Timeline is useful for larger projects over a larger time period.
So therefore my tip is… dont use timeline for your day to day small tasks if possible. Use it for larger projects. So if I have a project to start Monday, end Friday, then its good for the timeline, I can see my next project goes in next week then and do not overlap. But if I have a 5 minute task then its not in my project timeline, there is no need.
For all my tasks in the day I refer to my task list. To plan workload for my team we have a project planning board where large projects go and we use time line for that.
Nevertheless, timeline really does need Completed tasks gone. My tip is probably no good if using it for details project planning gantt charts in which you need all small tasks.