The so called fuel foaming is almost a thing of the past but it still happens so yes it is real. Not too many years ago it was a real problem and happened very often. These days the fuel is blended and uses an anti foaming agent in it so we don't really see it as often as most people think. One of the problems we had even when foam padding was used was people tended to pad the tank then tighten it in so much the padding was usless against vibration. I still pad my tanks but nothing like I used to. Most of my tanks are only padded on the bottom with fiber ties or velcro straps holding them in. I haven't had a foaming problem in years but it can still happen.