ATM middle click on the tempo selector resets the value 120. 120 is as suitable a default value as 130, 140 or any other value—indeed, it depends on the kind of music you are working on, unlike pan (default = centre) and volume (default = 0 dB) which lend themselves to having an intuitive default value. I would suggest either one of the following ideas:
1. Have a setting under Options > General where users can specify their preferred default tempo value. Then, middle-click on the BPM resets to that custom default value.
or...
2. Use middle-click to Type in value... instead of to reset.
Personally, I prefer suggestion 2 because my BPM choice varies quite a bit between projects, and BPM is one of those parameters that makes sense to set accurately. Also, the BPM selector looks a bit like a text box and I think a lot of users will find it intuitive to middle-click to edit.
Just one other small nitpick: when using the mouse wheel to adjust BPM, the mouse cursor turns into the dual arrowhead cursor. This cursor is bigger than the BPM digits, and completely covers up the digit you are trying to adjust, which means you can't see the value! My suggestion is simple: get rid of the dual arrowhead cursor. Instead, use the "pointing finger" cursor. In fact, get rid of the dual arrowhead cursor completely, everywhere—it's the least intuitive cursor ever created.
Middle click to type in tempo value (main window toolbar)
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