Combine rice flour and 2 cups cold water in a large, heatproof mixing bowl. Mix until smooth and velvety; set aside.
Soak dried shrimp in 1 cup cold water in a small bowl until softened, about 15 minutes. Drain and dry shrimp, then finely chop and set aside.
Boil enough water to immerse bacon in a small pot, and cook to soften, 3 to 4 minutes. Remove from heat and pat dry. Finely chop and set aside.
Heat 2 tablespoons oil in a wok over medium heat. Add shrimp and cook until fragrant, about 3 minutes. Add bacon. Cook for another 3 minutes. Remove from heat and set aside.
Clean the wok and heat remaining oil over medium-high heat. Stir-fry daikon and rock sugar for 3 minutes. Add 1 cup water, cover the wok, and steam daikon until just cooked, about 10 minutes. Remove from heat.
Add hot daikon mixture to the reserved rice flour mixture, mixing until daikon is well incorporated. Add bacon, shrimp, and salt; stir until evenly distributed. Pour into a 10-inch round cake pan and smooth out the top.
Bring some water to a boil in a wok. Place the cake pan on the wok rack, making sure the bottom half of the pan is immersed. Cover and reduce heat to medium. Steam until a toothpick goes cleanly through the center, about 1 hour. Check the water level regularly and replenish, if necessary, with boiling water. Remove pan and allow to cool on a rack for about 1 hour.