@Charles Dove Thank you for reaching out.
Azure Database Migration Service (DMS) can handle database migrations to an Azure SQL Managed Instance both in parallel and serially, depending on the configuration and the specific migration scenario.
In an online migration, data is continuously replicated from the source to the target, allowing for a more parallel approach to minimize downtime.
see the below doc for more information
https://zcusa.951200.xyz/en-us/azure/dms/faq
Regards,
Oury