The following urls can be used to access the various static HTML screens implemented by Automattic.
/wp-admin/admin.php?page=automattic&static=main
/wp-admin/admin.php?page=automattic&static=migration-cancelled
/wp-admin/admin.php?page=automattic&static=migration-progress
/wp-admin/admin.php?page=automattic&static=migration-complete
/wp-admin/admin.php?page=automattic&static=start
/wp-admin/admin.php?page=automattic&static=verifying