WIDesigner now has a
discussion board. For other users who might be interested, I'd appreciate if you could post these questions there, or with your permission, I can post them.
1. On the graph, the Blowing Level setting affects only the position of the blue circles. These mark the predicted playing frequencies, so in the table, the Blowing Level affects the predicted playing frequency (and the deviation).
2. Depends on where you start, and what you are optimizing. For most purposes, optimizing the hole layout from a plausible starting point (like another D whistle), DIRECT is (to be blunt) a waste of time. If you're optimizing a lot of interacting dimensions, such as hole layout and bore profile, DIRECT is less likely to get caught in a local optimum and miss a much better global optimum. If you're starting a long way from your target, such as starting from a D whistle layout to create an A whistle, DIRECT will explore a broader range of possible solutions.
3. Not a problem. The tuning file should have only the notes you want to optimize for.
4. WIDesigner does its internal calculations in metres. If the whistle calibration optimizer changed a hole position measured in inches, it was likely round-off error in the conversion from inches to metres and back.
5. (I'll need to take a closer look. It may be a couple of days before I get to it.)