For the orange sauce: Combine the vinegar, garlic, ginger, sugar, salt, chiles and oranges in a medium saucepan. Bring to a simmer, then reduce by half, 15 to 20 minutes. Strain, then add back to the saucepan.
Meanwhile, add 2 ounces warm water to the cornstarch in a mixing bowl and combine to make a slurry. Whisk the slurry into the sauce. Bring to a boil to thicken the sauce. Turn off the heat and set aside.
For the chicken: Add the oil to heavy-bottomed pot or Dutch oven, then place over medium heat. Clip a deep-frying thermometer to the side of the pot and bring the temperature of the oil up to 375 degrees F.
Combine the cornstarch, rice flour and 1 cup water in a bowl and whisk to form a batter. Add the chicken to the batter, then scoop half out using a spider or slotted spoon and add the chicken to the oil. Fry until crispy, 5 to 7 minutes. Remove the chicken to a bowl and add a few spoonfuls of orange sauce (you can add more to taste but start out conservatively). Toss to coat. Fry and sauce the remaining chicken in the same manner and set aside.
For the rice: Preheat the oven to 325 degrees F.
Bring 1 1/2 cups water up to a boil in a teakettle or saucepan. Place the rice in a strainer and run under cold water until the water runs clear, about 45 seconds. Set aside.
Melt 1 tablespoon butter in a medium ovenproof saucepan over low heat. Add the rinsed rice and salt and stir to coat. When the water has come to a boil, carefully pour it over the rice and bring to a simmer, stirring constantly. Cover the saucepan and transfer to the oven for 20 minutes. Remove the rice from the oven and allow to cool.
Melt the remaining stick of butter in a large cast-iron pan until foamy, then add the rice to brown on one side, about 5 minutes. Add a few shakes of sesame oil and soy sauce, then half of the sugar snap peas, half of the carrots and half of the cabbage. Whisk the eggs in a bowl, then scramble into the rice. Continue cooking until well-combined and slightly crispy. Combine the remaining vegetables into a slaw in a bowl and keep cool.
To serve: Warm the tortillas in the oven or on the stovetop until pliable. Spread a generous amount of mayonnaise on each tortilla, then add some fried rice, a handful of slaw and some crispy chicken. Drizzle with extra orange sauce. Roll and serve.