It would be very very useful to be able to zoom vertically the data within the tempo track. If my track tempo is set to 80 bmp and I want to perform small tempo changes, it's a nightmare to work with a a tempo track which shows the tempo range from 0 to 300... It would be much much easier I could zoom to, let's say, the range from 70 to 90.
Another thing: it would also help the possibility to add anchor points to change the tempo, just like automations. I add a point and I drag it. The current implementation is less user-friendly in my opinion and I ALWAYS end up ******** up something