Answer: The suggested thumb technique from Nyle Steiner, the inventor of the EWI and EVI is to rest your thumb LIGHTLY in the creases of the rollers (between the rollers) in a fashion so that your thumb is fairly perpendicular to the rollers. It's mostly a matter of practice. The other thing I regret to tell you is that it is my understanding that there was a software algorithm designed by Nyle in the original EWI that made going over the octave breaks smoother. I immediately noticed that I was having a problem glitching on octave breaks on the 3020 when I never had this problem on the 1000. Nyle confirmed that Akai left this bit of programming off of the 3020, DON'T ASK ME WHY! 

The 3020 does have a unique feature called "key delay".  The object of this programming parameter was to address complaints from players that the touch sensitive keys were too sensitive and they were getting unintended notes or bends.  The higher the key delay setting the less sensitive the keys are to touch.  The key delay feature affects everything on the controller including the keys, rollers, bend plates and portamento plate.  Setting to about 12 or so, you should be able to play the octave breaks very smoothly.  Advanced EWI players, however, prefer to set the key delay to zero.