how does brush angle jitter work?

I am exploring angle jitter for brushes in the latest PS CC. I am using a brush which is a 1 px thin horizontal bar at width of about 160 px, and I draw across or down, producing a chain of bars at various angles. In this exercise, the only brush setting is for angle jitter.

(1). Is the following correct?

When control is off, for angle jitter setting of x%, it seems that, for each separate stroke, the angle is mostly plus/minus 8% (of something) or  0 relative to an invisible horizontal line across the drawing surface, independent of stroke direction. (So the bar is either horizontal, or tilted somewhat up and down regardless of stylus movement).There are other angles. but these seem to me to appear less (I may have a biased eye.). So each angle is a sample from a fixed distribution which seems to have peaks in the middle and at the ends. (Hard to know exactly.) This is useful.

In any event, when control is set to "pen pressure", it behaves completely differently. The angle seems to take a random walk in a circle, with the "step size" given by x% of something. This is very different, as now all angles appear and the draw stroke is, for me, most unintuitive and less useful.

(2). Can I do the following?

It seems to me that, with pen pressure, the angle still should be drawn from a fixed distribution,where the width of that distribution should depend on pressure. Then, with low pressure, there are only small angles, and with larger pressure, there are larger angles but the angle still bounded depending on the jitter setting and having the same (scaled) distribution. It would also be very nice if the angle could always be perpendicular to the pen direction (which is effectively what happens for a vertical stroke.)

Thank you.