Can I get an X2 visa in Korea?

Im an Indonesian and I just got accepted at a school in Beijing. I have all the documents needed for an X2. I currently have a plane ticket to Beijing on the 15th of August. However, I plan to visit Korea a week after I arrive in Beijing and return to Beijing before my school starts in early September.

I currently have a residence permit from my last school which expires on the 30th of August. I plan to use that permit to enter Beijing, leave for Seoul sometime before the 30th of August, get my X2 processed in the Chinese embassy in Seoul, and then reenter China with the X2. Is there anything wrong with this plan?