I've been doing this for decades with various machines - Singer; White; Viking and never had an issue with any of them. Then again, I don't think it's even possible with the presser foot down. That would be the only issue I could think of as there would be much more pressure on the tension discs and the thread would break leaving the possibility of tiny pieces of thread that you might not be able to see/clean out. Otherwise I agree with whomever it was that said if a machine is that delicate, do you really want it????