Annotating music with this system has proven to be a dumpster fire.  Despite every effort with the zoom feature & the stylus, it just doesn't work.  The mane problem is the resolution is too low.  Even 1080x1920 wouldn't be high enough resolution to simulate writing tiny numbers on paper.   Every pixel has to count so cursor movements are real slow, trying to hit the exact pixel.  Drawing accurate lines with fat pixels is real hard.  Constraining to certain angles might be necessary.

The zoom level makes a slight difference, but it still feels like the cursor is always on the edge of 2 pixels & you have to move very slowly to hit the right pixel.  The stylus isn't as smooth as hoped.  It sticks & stutters along.  It's not much better than drawing with a joystick in 1984.

The line tool is slow but accurate for drawing text.  The pencil tool can draw slightly faster but very messy text.  The circle tools are essential for drawing notes, but it's real hard with fat pixels.  The pencil tool has only been useful for drawing dots.  Hollow & filled ellipses for the pencil tool might make it faster for drawing notes than the circle tool.  A virtual keyboard & a text tool seem to be the biggest need. 

Maybe a capacitive touch screen should replace the track pad, but that's an expensive proposition.  It might be time to reconsider a trackball.  There's also going with a small mouse or using a phone screen as a track pad.

This system might still have potential for notation capture, since that doesn't involve any manual drawing.  The sizes of all the symbols can be fixed, so the precise positioning of fat pixels can be automated.