The premium stacked slow rise day night roller shade with a 1-1/2” black blackout and charcoal sun shade requires a minimum inside mount depth of 2-1/2 inches. Your cornice depth of 2-5/8 inches provides only about 1/8 inch of clearance, which is quite tight and may not allow for proper installation or smooth operation. For best results, a deeper cornice is recommended. However, choosing a stacked roller setup can help maximize space and functionality in your current cornice dimensions.