Currently, we can see our best time for the highest greater rift we've completed with each type of character. But I would also love to see my best time for each greater rift level. For example, even though I can complete level 65 greater rifts, I'd still love to see my fastest time for a level 5 greater rift, or level 25 greater rift.
This would make it enjoyable to attempt speed runs on each greater rift level and would promote speed builds that balance speed and damage. It adds a lot of replay value to lower level grifts and makes leveling up gems a bit more enjoyable. Imagine what the Leaderboard times for a level 1 greater rift would be!
It's easy to implement, adds another fun solo goal to play towards, and adds another level of competition to those looking for world's best times.