Citizenship

Hello!
I just passed my naturalization interview very recently and I am extremely happy about this! I will post more information in a separate thread but for now I want to ask for advice how to handle my situation.
I am German citizen and I would like to retain my German citizenship. Germany doesn't allow dual citizenships unless they issue you an retention approval certificate. Accepting any other citizenship prior to receiving the German approval will result in loss of the German one.
So I have filed the application for the German retention last year in Spring and I was told it would take no longer than 6 months. To be on the safe side, I waited 3 months and sent out the N400 for the US citizenship. I haven't heard since and when I called the German embassy I was told the processing time of the application is 12 -14 months due to a high volume of applications.
At the naturalization interview the IO told me that I will attend a judicial oath ceremony relatively fast approx. 2-3 weeks (I am also changing my family name).
I am extremely happy and honored to become US Citizen but at the same time I'd also like to retain my German citizenship because it is a very strong passport and allows you to live in Europe which is a huge privilege.
So I would like to know if there is any legal way to delay or reschedule the oath ceremony to get some downtime and give the Germans the chance to process my retention application asap. I am already calling and email them every day and doing my best to speed up this process!!!
Please let me know if you have ever had to reschedule the oath ceremony and please let me know how long it has taken you from the day of the interview to the oath ceremony? I will appreciate every answer!
I am based in NYC.

Thank you!