"Unfortunately, there are no corrective actions that you can do to prevent this issue. Limit on the log rate is the price that must be taken to always ensure that the backups are taken.
If you are migrating your databases from SQL Server to Managed Instance you can repeat this experiment on your SQL Server instance to check what are the instance log limits that you have and could your workload run on the Managed Instance with the same performance. Just make sure that you are using the version built for your version of SQL Server."
Source: Log rate throughput cap on Managed Instance.
Jovan was part of the team that brought to live Managed Instance although he is no longer serving in that team, for me he is the must trusted source about Managed Instance even over Microsoft Learn.