What kind of Azure SQL do you want to deploy?
Azure SQL Server in a VM
Azure SQL Database
Azure SQL Managed Instance
In the case of a PiT on an Azure SQL VM, there are no differences between Azure and your data center, you are responsible for setting up the backup for your SQL Server.
In the case of a PiT on an Azure SQL DB/MI, the service has the backup/restore included, and it is scheduled automatically => you can't change it.
There is no correlation between sizing and PiT restores.
This is a General Purpose Azure SQL Database btw.