Soak rice in a large bowl of water until mostly translucent, about 4 hours. Rinse and drain thoroughly.
Soak mushrooms, shrimp, and scallops in 3 separate bowls of water until softened, about 15 minutes. Drain, reserving mushroom water and discarding other water. Chop mushrooms, shrimp, and scallops into small pieces.
Heat olive oil in a large skillet over medium heat. Pour eggs into skillet, swirling to spread out into a thin layer. Cook until mostly firm, about 1 minute. Flip and cook until no longer runny, 3 to 5 minutes.
Transfer egg to a cutting board and allow to cool slightly. Roll into a long tube and slice into thin ribbons.
Stir Chinese sausage into the same skillet over medium heat. Cook and stir until fragrant and some of the oil is released, about 3 minutes. Add mushrooms, shrimp, and scallops; cook for 3 to 5 minutes. Transfer sausage mixture to a bowl.
Stir drained rice into the skillet. Cook and stir until lightly toasted, 1 to 2 minutes. Pour in reserved mushroom water, stirring constantly until water is absorbed. Add hot water, 1/2 cup at a time, stirring until water is absorbed between each addition. Cook until rice is softened, about 25 minutes.
Season rice with light soy sauce, dark soy sauce, and sugar. Stir in egg ribbons and sausage mixture. Top with cilantro before serving.