Regarding recomended project copy includes EPS structure

To whom it may concern,

I'd like to know the best way to make a copy of EPS/project.

I need to make a copy which includes 100 EPS and 10,000 projects.

Could you please teach me the recomended way to do it??

I think there're 2 ways below.

  <1> In Project screen, copy projects and EPS at the same time.

  <2> In EPS screen, copy projects and EPS at the same time.

In case of <1>, the error happened when the number of projects are more than 1,000. But it is faster than <2> if the number of projects are less than 1,000.

In case of <2>, there's no error. But it takes 10 times longer than <1>.