Is It Possible to Overproof Sponge?

Hi, I am brand new to this site and fairly brand new to bread baking. I have a French bread recipe that I've made several times with reasonable success (I'm assuming this is true since my kids circle like sharks around the table while it's baking:) but I would like to do something that would add depth to the flavor of the finished product. I wondered if I could extend the fermentation time of the sponge from 2-3 hours to perhaps overnight without negative consequence, and if this is possible, would it produce an improvement in the depth of flavor, which is what I am seeking. The recipe is a very basic one that calls for bread flour, salt, yeast and water only.

Thanks in advance for any suggestions you may have. I'm posting the recipe below for more detailed information:

French Bread

Sponge:  1 tsp. active dry yeast, 10 oz. bread flour, 1 1/2 cups warm water (approximately 80 - 90 degrees F)

Dough:  1 tsp. active dry yeast, 1/4 c. warm water 80 - 90 degrees F) 14 oz. bread flour, 2 tsp. salt (preferably kosher)

Method

1. Prepare sponge: In a large mixing bowl, thoroughly mix sponge ingredients. Cover and let rise at room temperature until the mixture looks bubbly and is at least double in volume (see video). Approximately 2-3 hours.
2. Make the dough: In a small bowl or measuring cup, stir one teaspoon yeast into the ¼ cup of water and let sit for a few minutes until softened (dissolved).
3. Add the softened yeast, 14 oz. bread flour and salt to the sponge. Stir with a spoon to incorporate ingredients well. If dough feels dry, add a bit more water. If it feels too wet, add a little more flour. Make adjustments, if necessary, in small increments (one tablespoon at a time-or less).
4. Empty dough onto table and knead for 8-10 minutes, using as little four as necessary to prevent the dough from sticking. This may be done using a heavy duty stand mixer and mixing on speed two for 5-6 minutes or speed one for 10 minutes. Use the slower speed if your mixer sounds as if it is straining.
5. Round the dough and place back in the bowl. Cover and let rise until double (usually between 1-2 hours).
6. Divide the dough into four pieces and round each piece. Cover and let rest for about 10 minutes. .
7. Follow the video for the shaping, rising, slashing, and baking of the loaves with steam.
8. Loaves will bake in approximately 20-25 minutes at 425°F. There should be a hollow sound when the bottoms are tapped. Be careful - bread is very hot!
9. Enjoy!