I found this tool very useful when I worked on some italics last week. Thanks for publishing it!
Here is a thought (or a feature request):
When designing an italic, it’s often not possible to get the exact angle, because of integer coordinates. Think about the angle of the bars of a sans-serif E, or a hyphen. In that case, my personal rule is: (1) make the angle as close as possible to the precise angle, and (2) the angle must not be greater than the precise italic angle.
For example, if the angle is 11.3099 degrees (1:5 ratio), and the hyphen has a thickness of 14, I’ll give the terminal 2:14 even though 3:14 would be is closer, but it would be greater than the precise angle. Hope this makes sense.
Would it be possible to implement that reasoning, so that the tool does not complain when I have 2:14?