I watched the video and the method is not very precise. I'm not sure how you
end up with a nice looking quilt like that. It would drive me crazy for sure.
I'd probably poke a few holes in my fabric. LOL
May I suggest you use a different method such as in the video below.
I would also recommend that you starch your fabric before cutting
because you will be sewing on bias edges which tends to stretch.
Check other tutorials through google. It's called Economy Patch quilt block.
https://www.youtube.com/watch?v=Ow_zVqQ-7yc