What are some potential innovative applications or design modifications that could be integrated into electric skateboards to further enhance their commuting capabilities, and how might these advancements impact the overall user experience in terms of efficiency, safety, and environmental sustainability? For instance, could the incorporation of advanced regenerative braking systems, customizable ergonomic designs, or AI-powered route optimization algorithms significantly improve the performance and appeal of electric skateboards as a viable commuting option? How might manufacturers balance the need for increased power and speed with the necessity of maintaining a safe and stable ride, particularly in densely populated urban environments?