We too are also keen to see this functionality. Our application is hosted in the same AWS region as the MongoDB databases, but because they are in different AZs, we are getting increased data transfer costs. It would be helpful to either a) be able to set which AZs mongodb should spin up the clusters in, or b) be able to see which AZs mongodb has been spun up in so we can move our EC2 instances into the same AZ. This would help us cut $100s per month off our data transfer costs.
We too are also keen to see this functionality. Our application is hosted in the same AWS region as the MongoDB databases, but because they are in different AZs, we are getting increased data transfer costs. It would be helpful to either a) be able to set which AZs mongodb should spin up the clusters in, or b) be able to see which AZs mongodb has been spun up in so we can move our EC2 instances into the same AZ. This would help us cut $100s per month off our data transfer costs.