I really need the Stylus curve options for adjusting how any tool responds with options like Pressure, Tilt Direction/Angle/Azimuth, and Barrel Rotation. These are tools currently available in a number of free programs and the code for them can be found available through open source drawing and painting applications (like Krita, MyPaint, and GIMP). Without having these, using tools like pencil or chalk means not being able to control and adjust the settings in a way that feels natural, resulting in my having to swap between multiple different tool settings any time I go to transition from bold strokes for filling to sharp points. The same is true for loading controls for Oil Brush, application of thickness of paint in custom brush, and so many more. Merely controlling options through pressure control in the tools themselves is limited and doesn't have the full range of control that someone sensitive to how my tools handle in traditional media should behave in digital media.

Sadly, this lack of controls has been keeping me from suggesting others use it over alternatives available now. Hopefully they can be added sooner rather than later.