How to change kubernetes api-server flags [AKS] [Kubernetes 1.8]
Support for the aggregation layer has been added a couple weeks ago, so no configuration should be necessary for a new cluster. Please see details here: https://github.com/Azure/AKS/issues/54
AKS now supports aggregated API - you can find specific scaling details in the following GitHub comment @ https://github.com/Azure/AKS/issues/77#issuecomment-352926551. Run "az aks upgrade" even to the same Kubernetes version and AKS will update the control plane with the required certificates on the backend.