Yeah, I was really surprised to see the action on them hoses, too! I thought the mufflers would smoothen the puffs out but no. I also tried wrapping a blanket around them to keep them in place but it didn't work for long.
I'm hoping we won't have too much work in the garage that will involve a running vehicle. I'm going to try to get by with the flexible duct work for now. If we hadn't decided to move I'd look at a more permanent solution. The transmission blanket is heavy enough to control most of the movement.