Based on your profile and your interests, if I were you, I wouldn’t “waste” your REA on Harvard.
A GPA of 3.85, while in the top 5% of higher of all colleges applicants overall, is still in the bottom of the mid-50% of accepted students, if not in the bottom 25% (their average last year was 3.95). That means that, while you still are competitive, your chances are most likely below average. Average acceptance rate is less than 5%. Now, while REA acceptance rate is 13.4%, this includes recruiter athletes with acceptance rates of 80% or higher, legacies, kids of donors, kids on special lists, etc. Non-hooked kids are likely closer to 7%, and kids whose stats are below average of the accepted students are likely even lower than that.
There are many top schools at which your profile + ED application would put you in a pretty high chances of acceptance category. For Harvard, it may move you from 2% (RD) to 4% or 5%. Realistically speaking, a 95% chance of rejection isn’t that different from a 98% chance of rejection.
Good luck, though. As I wrote, your stats make you competitive for a very large range of very good colleges, so I recommend that you start looking through these colleges to find those which are a good fit for you.