This documentation page talks about how to manage shard balancing - https://www.mongodb.com/docs/manual/tutorial/manage-sharded-cluster-balancer/#schedule-the-balancing-window
but it requires connecting to the db first, I see no way to manage this through the Atlas Gui or terraform.
We have had some instances recently where shard balancing has caused a large resource usage spike on our cluster and affected our services and we would really like to be able to set a shard balancing window using terraform to prevent this from happening during the middle of the day