It depends what you learn from it and how you use it in your personal statement. The Open University courses wont boost your personal statement nor your application but if you learn something from it or it made you want to do the course you want to apply for, it will make your personal statement more personal to you, which is a good thing to do for it. If you can't be bothered with doing them, dont do them. I tried to do a law mooc and I just couldnt be bothered but I have other things I like doing I can put in my personal statement, which you will too since there is so many things to do for your course.