Migrate Launchpad bugs to GitHub Issues > trigger abuse detection

Based on this answer I'm trying to migrate my project bugs from Launchpad to GitHub. With both tools LP2GH and github-issue-importer I'm running into an abuse detection trigger

exception: {"message":
               "You have triggered an abuse detection mechanism
                and have been temporarily blocked from content
                creation. Please retry your request again later.",
            "documentation_url":
               "https://developer.github.com/v3#abuse-rate-limits"
           }

_{This is from LP2GH}

If I wait for a while and retry to migrate they will both start from scratch, create duplicate issues and end up at the same issue as before (again with an abuse trigger).

How can I migrate all bugs?

I ended up adding a failsafe method to lp2gh which will retry after a minute. A pull request is pending.