Which door is used when the L1 door is unavailable to avoid aircraft tipping?

The L2 door is used when the L1 door is unavailable to avoid aircraft tipping because it provides a balanced entry and exit point for passengers. When the L1 door is compromised or not usable, having to rely on the L2 door helps maintain the aircraft's structural integrity during boarding and deplaning. This is particularly important in smaller aircraft where the balance can be easily affected by passenger movement. Using the L2 door rather than any of the other options ensures that the weight distribution remains even, mitigating the risk of tipping, especially during critical phases such as boarding or deplaning.