It would be nice to have the option to show only certain sports in a timeline. And in addition to that, having the option to set avg pace/speed and minimum distance parameters that will filter out all trashy results from others. For example, I'm a runner, and I don't want to see any bike/swim/hiking/etc from others, nor running results shorter than 10K or results with a lower avg pace than 5 minutes per km. This way it keeps my timeline interesting to read once in a while. 🙂
The same avg pace/speed and distance parameters should also be available for Clubs Leaderboard admins, to show a bit of the same results in its overview. As a result it will remove people from the list that have a "running" Distances of 100 km at 6:30 /km and will leave the people who performed way better with Distances of 90 km at 4:00 /km in perspective. I know admins like many more options like region, age, amount, and elevation. But I think the most important ones are pace and minimal distance.