Scott Manley (YouTube space/rocket guy) did a quick video on it.

With this type of compressed air system you only get a few seconds of operating time since the tank pressure gets reduced/depleted very rapidly, but at max pressure there's about 8 tons of thrust vs 2 ton vehicle weight, so there is no problem with the physics.

There is a much bigger tank for the arial flip/hover, that takes up the entire passenger area, and a smaller one in the rear for the 0-60 boost, but for either stunt you've only got a few seconds of air pressure.