I have just read an article about upgrades on Mini Titans from an old edition of MHW (July 08) kindly provided to me by Russell Gasper. It mentions changing the delta angle on the head by reducing the length of the blade holder ball link arms by 5mm to cure miss-tracking. I have had a look at the original plastic head grips and the arms are the same length as the T/T CNC ones, with which I also had tracking problems, however, the Sonix head is made with shorter arms to introduce delta as standard. I have looked at pictures of the Kasama head and that appears to have the provision to move the link ball to introduce delta if needed.
Maybe that's the reason that the Sonix head tracks so well.