The highlight tool is still very glitchy.
It sometimes expects a drag left to right, and sometimes right to left. There is no way to guess which one it is. If you guess wrong, a huge chunk of irrelevant text suddenly becomes highlighted. Please make it consistent.
Also, it can be difficult to get an erroneous highlight to delete. Outside of the annotations menu, I right click and see "delete highlight." I sometimes have to click that many times, and sometimes it deletes the highlight from one word at a time instead of the entire section.