Drawing arrows and double headed arrows with Apple Pencil 2 using Scribble in iPad OS 14

As Apple’s explanation of iPad OS 14 states, if you draw a shape and leave the Apple pencil resting on the iPad for a moment, shape recognition straightens the lines.

I have not seen the following documented anywhere, but if you draw a line and without lifting the pencil, retrace the end of the line and leave the pencil resting on the line for a moment, it turns the line into an arrow.

If you draw a line retracing both ends of the line and leave the pencil on the iPad for a moment, it turns it into a double-headed arrow. The following movie illustrates using Notes on an iPad Pro (2018). I demonstrated this in this YouTube video.

Does anyone else know of any other shape recognition features other than the documented squares, rectangles, triangles, circles, ovals and stars?