Best practices for first period load in FCCS

Summary:

What is the standard practice /general best practice to load the first period in FCCS?

We have fccs environment and we are going through a change in the ERP system and the CoA are changing. We fixed a lot of retained earning issues we had in ERP and due to that we have decided to load the first period data directly from FCCS

We only want to keep the data from FY20 onwards. How do you load the first period data?

Would you load post elimination data for the first period? How do you load RE when your current year RE has IC eliminations?