Zapple Pie with a Streusel Topping

Ingredients
6 cups peeled, quartered, and thinly sliced zucchini (about 2 pounds)
3/4 cup sugar
2 teaspoons ground cinnamon
1/4 teaspoon ground nutmeg
1/2 cup plus 2 tablespoons fresh lemon juice
1/3 cup unbleached all-purpose flour
1 unbaked 9- or 10-inch pie shell
Topping
1/2 cup unbleached all-purpose flour
1/2 cup packed light brown sugar
1 teaspoon ground cinnamon
4 tablespoons butter
1 cup chopped pecans or walnuts
1. To make the filling, in a medium saucepan over medium heat, combine the zucchini, sugar, cinnamon, and nutmeg. Add the 2 tablespoons lemon juice. Stir to mix and cook until tender but not mushy, about 15 minutes, stirring frequently.
2. In a large measuring cup or a small bowl, dissolve the flour in the remaining 1/2 cup lemon juice. Stir into the zucchini mixture. Continue to cook until the mixture thickens, 2 to 3 minutes. Remove from heat.
3. Preheat the oven to 450ºF.
4. To make the topping, combine the flour, brown sugar, and cinnamon in a small bowl. Using a pastry blender or two knives, cut in the butter until the mixture is crumbly. Stir in the pecans.
5. Spoon the filling into the pie shell. Top with half of the streusel topping. Place in the oven and reduce the oven to 350ºF. Bake for 30 minutes, until the crust is browned and the filling is bubbling.
6. Sprinkle the remaining toping over the pie. Turn on the broiler. Run the pie under the broiler for about 3 minutes, until the topping is browned.
7. Set the pie on a wire rack to cool. Serve warm or completely cooled. It is best served on the day it is made.
Serves 6-8
Credits: From The Classic Zucchini Cookbook by Nancy C.

Can the filling be pre-cooked and stored in the fridge after step 1 or 2? Or will it be too cold/get too mushy by the time the 30 minutes baking time is up?

Dave