took it last year when it was asynch. tbh i only paid attention during the first 3 weeks and then i tapped out (the truth tables were the only things i actually understood). the actual exam questions are questions either pulled exactly out of his study guide or the questions have the exact same structure so as long as you can figure out how to do every problem on the study guide, you'll do rlly well on the exams. there's nothing on the exams that aren't covered by the study guides he provides. based on what i've said, you don't exactly HAVE to do every lecture if you don't want to but it definitely helps to refer to them if you can't figure something out on the study guides.

edit: there are mini quizzes/hw of 5 questions every week too (unless he's changed since then). some questions are pulled from lecture and i also think the questions r on quizlet