Workplace interruptions significantly disrupt productivityand well-being, particularly during periods of highcognitive load. Existing intelligent management solutionsoften fail to account for the complex social boundaries andstrict privacy requirements inherent to in-situdeployments. We introduce a comprehensive set of designguidelines for future cognitive load-based systems thatbridge this gap between controlled laboratory settings andthe real world. Our approach integrates 'Privacy byArchitecture' and 'Contextual Lifecycle Awareness' intocooperative systems to ensure data sovereignty whileutilising eye tracking for physiological state assessment.These guidelines facilitate the development of fail-safesystems that effectively mitigate disruptive interruptionswhile fostering user trust and acceptance.