Retry attempt #1 is meaning you did receive a error on the API call its retrying.
When you hit rate limit will probably see more the one attempt mostly #3 or even #4 (there is a backoff strategy implemented)
you can only migrate stuff that not able to fetch history of.
So portfolio data / investments (if you have added them) and
battle_big.csv and losing_big.csv
RE: The Splinterlands Stats Tool Reborn