I do, if they aren't used with words that are commonly hyphenated. Hyphenating to cram 9 or 10 words into a Six is defeating the point of the art form, in my humble opinion. If you have a hard time saying it in six, rephrase and use the backstory function - isn't that what it's for? Sorry for the rant, and I am most definitely NOT the 6WM police. Just stating my preference.