Since this course contains multiple FPGA boards, some of which you may not have, I understand that you do not want to watch ALL lectures to get the 100% completion certificate at the end. This is an article that Udemy has provided. You can mark the lectures you do not want to watch as complete and follow along with which board you are using. Hope this helps!
Lectures will be automatically marked as complete once you have watched every minute of the lecture, but, if you need to manually mark the lecture as complete, you can easily do so.
To learn how to mark or unmark a lecture as complete, please read below.
Lectures Marked as Complete
Lectures that have been completed will have a checkmark to the right of it on the course dashboard, or the curriculum navigation in the video player. If the circle is blank, however, then the lecture is not marked as complete.
Mark a Lecture as Complete From The Course Dashboard
One way to mark a lecture as complete is do so from the course dashboard.

You can also mark a lecture as complete in the curriculum navigation, which you can access in the video player.

Unmarking Lectures as Complete
If you mark a lecture as complete by accident, or decide you wish take a lecture again and want its completion reset, then you can mark the lecture as incomplete. To do so, please follow the same steps outlined above, except in this case, you'll need to click on the completed checkmark to remove it.