Place 2 cups flour, baking powder, and sugar in the bowl of a food processor or blender; pulse a few times to combine. Add shortening; pulse until mixture has the consistency of fine crumbs.
Place flour mixture in a bowl; stir in white chocolate, blueberries, and orange zest. Stir milk into flour mixture gradually to form a smooth batter. Turn mixture out onto a floured board; sprinkle with remaining 1/2 cup flour. Knead a few times to incorporate flour and form a smooth dough.
Roll dough out 1/2-inch thick; cut scones with a biscuit cutter to desired size. Place scones on a baking sheet.
Bake in the preheated oven until golden, about 15 minutes.