I've been noticing that for some reason I can't seem to improve my execution while using the stick on my lap, so I tried sitting on the floor like some pros do at tournaments, while at the same time changing the grip on the lever (from Old Daigo style, lever between pinky and ring finger, to using the hand normally, using the palm. Daigo seems to have reverted to this technique during the 25th Anniversary finals). The result was astounding: I can suddenly pull my double quarter circles easily on both directions, something that was hard and inconsistent while on the lap, although it's a different story to what it does to my back without a back support.
Could there be some relation in the arm position and the execution improvement?
Any other tips and techniques on improving execution on fast motions and especially while sitting with the stick on the lap in a chair?