Creating a customized pressure cooker for cooking rice in large quantities, specifically for 100 to 500 people, poses significant safety risks, including potential explosions if not designed correctly. The discussion highlights the importance of adhering to safety regulations, as large-scale cooking equipment must be constructed and inspected to meet public liability standards. Many participants suggest that purchasing an existing pressure cooker, which costs around $50, is a safer and more practical option. The risks associated with DIY pressure cookers are emphasized, with warnings about the dangers of improper construction. Overall, the consensus leans towards caution and the recommendation to consider safer alternatives like steamers.