Explanation:
Box 1: Azure SQL Managed Instance
Managed Instance will support native BACKUP like SQL Server.
COPY_ONLY Backup
Once you create a credential, you can backup any database using standard BACKUP T-SQL command:
BACKUP DATABASE tpcc2501
TO URL = 'https://myacc.blob.core.windows.net/testcontainer/tpcc2501.bak' WITH COPY_ONLY The only mandatory property is COPY_ONLY. Azure SQL Managed Instance owns the backup chain. This means that you cannot perform database backup that breaks the backup chain. Azure SQL Managed Instance allows you to perform only COPY_ONLY backups.
Box 2: Auto-failover group
For geographic failover of instances of SQL Managed Instance, use Auto-failover groups.
The auto-failover groups feature allows you to manage the replication and failover of some or all databases on a logical server to another region.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/automated-backups-overview
https://docs.microsoft.com/en-us/azure/azure-sql/database/auto-failover-group-sql-db