A deliberate and decisive spin to the right on the dormant controller will activate the Smart-X on that controller, which then will lock out and prevent interference from the other, until the same deliberate action is performed on it. There is an intelligent algorithm in my code which can discern this deliberate action, while ignoring bumps, vibration, etc. in order to prevent unintentional switching.
This only comes into play when a user has a trackball connected to their TurboTwist 2 spinner interface (the new version with Opti-Wiz 3 technology.) This has several advantages: Efficiency - the interface only uses a single device report for multiple controls, Cost - an extra interface for a trackball is not necessary, and Ease-of-Configuration - the X-axis mapping is always the same, regardless of whether it is a spinner or trackball game, and no need for extra command line options to keep both controls from being active simultaneously.