Hi Jerryblu,
I don't know if the Reverse Barrel Roll is a standardized figure in your country. But in the UK in appeared as a popular variation in 1972, published by the ISTD, UK. I agree with you that figures timed 1 a2 are the most popular. Also these figures have a bounce or pelvic action or both. A figure such as the Barrel Roll has neither. The action is from the waist upwards in which trunk of the body is rolled in a tight circle. This is why we used the timing of S,Q,Q,S,Q,Q.