Hello,
What i understand is that one lot is in 1st plant whereRR and UD both required now QI qty posted in 2nd plant where RR not required but UD required based on first plant decision.
For this, there is not a single key object through which UD cpoied from one plant to another plant lot. Object means Batches are different, Inspection lot offcourse different. If you use any exit or enhancement then system need any single object so that based on it system will copied the UD code. Not possible take manual call before closing the lot .
Regards