Megan Boyd has a good post at Lady (Legal Writer) on the use of forms in legal writing. She does not ban them, but she does offer some wise cautionary advice on using them.
I am not a fan of writing from forms, at least in persuasive writing. See, for example, this old post. I can see their usefulness when the purpose is not persuasion. If you must use them, follow Megan’s advice. And take a look at these old post from 2007 and 2009.