Duke Alumni Interview Priority Deadline: How much does it matter?

The RD alumni interview priority deadline is 12/20 (all application materials submitted) vs. RD which is 1/2. Does anyone know if submitting by the interview priority deadline is important/shows demonstrated interests? What should I prioritize between submitting by 12/20 and polishing essays that are close to done by 12/20 but could possibly be better by 1/2? Thanks!