I can get DCS to so called 'snap roll' if I apply aileron in the direction of roll... but this is not the 'official snap roll', which is the application of elevator and rudder only - as the guy does in that AG video.
He then applies momentary and then opposite aileron, after the roll, to help bring the wing out of stall.
Maybe a full fuselage tank might help, but this is not the idea
.