Hi @mono-developer, thank you for your request. However, there is no open way to pause the tracker since it would destroy the experience for all other apps. It would require the need to keep track of the state, which tracker is on and off (especially in a multi tracker scenario) etc.
As it stands the only means of turning the LEDs off is via the Tobii Interaction Software within the Windows System Tray.. we do however hope to implement a global keyboard shortcut to make this process easier, but pausing the tracker within the API is something not planned for the future. My apologies for the inconvenience.