Hi Kevin,
Your process is correct. You should be fine. The key is to run the DIC and rebuild after, and balance your reports as you have done for the costs.
Alternatively, you could have used the GV RW to revise, but the import is cleaner and is the quicker route. With GV RW you would still have to do the DIC.
If you are unsure of the impact, we would also suggest that you do a GV of the affected files and compare with your expected results after the import and DIC.
When you go to do live, make sure you have retrieved and posted all cost batches from AP or POA, or Payroll before doing the import, to ensure you have a clean cutoff.
Best,
Brian