What are the specific technical conditions under which suspension lockout should be employed on the road to maximize efficiency, and to what extent does the ratio of rider weight to bike weight influence this decision, considering factors such as cadence, terrain variability, and aerodynamic drag? Should road cyclists primarily rely on the lockout feature to suppress unwanted vertical motion and energy loss during high-intensity sprints or prolonged climbs, or would a more nuanced approach involving selective engagement and disengagement yield better results in terms of overall speed and power output?