Ever since the first iteration of the editor, changing the bpm via the buttons shown above will increase/decrease the bpm by a seemingly arbitrary decimal value. Since most songs don't use decimal bpm, it would be a welcome change to rework these buttons so that:
-Clicking by itself will change the bpm by 1
-Shift-Clicking will change the bpm by 5
-Ctrl-Clicking will change the bpm by .5
-Alt-Clicking will change the bpm by .25
I see this as more efficient than changing it via the timing panel, and it will likely speed up timing variable bpm songs. And of course, you would still have the option to change it via the timing panel.