Anyone applying to Georgetown/did apply in the past, if I choose to submit my application with everything completed except for an optional recommendation letter, can my teacher still add it even if my application is submitted? I already have one required letter in, but if I want to submit without an optional one, do I have to add that to the portal too before I fully submit and send everything? Or can I submit my essays and add the rec letter later?
Might be too late in answering now but, I’m pretty sure that your teachers can still submit recs after you submit your application. This is an excerpt directly from the Georgetown portal on the Recommendation request section.
"Please note, you can access this portal after you submit your supplement to monitor the receipt of your recommendation letters. "
Good luck 
Thank you! My teachers submitted everything yesterday so we’re all good!