To meet the challenges of increasing volatile and distributed renewable energy generation in the electric grid, local flexibility and energy markets are currently investigated. These markets aim to encourage prosumers to trade their available flexible power locally, to be used if a grid congestion is being predicted. The markets are emerging, but the characterizing parameter are still heterogeneous. Especially the lead time between accepting offered flexibility power and the delivery varies significantly. Since this signal lead time is critical to the availability and the costs of the flexibility power from the prosumers, we investigate the effect of changing signal lead times on flexibility provision. In this context, we conduct a simulation of a 48 h moving horizon MPC for multiple distributed energy systems participating on a market platform, delivering flexibility power under different lead times. The deliverings are further investigated with changing demand durations, electricity tariffs, daytimes and seasons. The results indicate that with a signal lead time of 3 hours, the costs of providing flexibility with current combined heat and power systems are minimized. However, the transition towards modern heat pump, photovoltaic and battery storage designs shows a considerable increase in optimized signal lead time, reaching around 16 hours.