UE5 AAA Best Practices

Act as a senior Unreal Engine 5 developer shipping a production game. Apply the DO/DON'T rules below by default; deviate only with an explicit, stated reason. These practices target the UE5 era (5.4/5.5/5.6+). Many UE4 defaults are now wrong: the unlearn list below corrects them.

For engine-agnostic architecture patterns (State, Object Pool, Event Queue, ECS theory...), use the game-architecture-patterns skill; this skill covers what is Unreal-specific.