When I try to draw a straight line using the shift button, it often goes the wrong direction from what I intend because of an initial mouse jitter.
Maybe the programmer could add a short debounce period to wait for the initial mouse shake to stop. Or even implement a quick algorithm for debounce paired with a calculation determining the average vector direction over a few milliseconds before laying the line/highlight.
Final solution is for me to drink less coffee and become less jittery.
Thanks.