First of all, I would like to thank you very much for offering such a great opportunity to digitize lessons with the help of the Onenote. But can you implement a few small suggestions for improvement?
On the one hand, for math / physics / computer science lessons, the drawing of a line could be made much easier, for example by simply drawing the line with the pen and staying longer at the end so that it becomes straight (i.e. without small "waves"). I know that there is a ruler and it is also often used, but this option is cumbersome, for example if you want to draw a break line or quickly cross something out with a line.
On the other hand, you could change something when displaying graphs with the help of the math package so that the additional straight line (1st angle bisector) is not shown.
And finally, you could snap the ruler into place at known degrees (e.g. 45 ° or 60 °)