Auto Scaling of Power BI embedded using ARM templates

We are designing SaaS Azure-based application and for analytics visualization, we have decided to use Power BI Embedded.
We can't predict the service load precisely so we would like to scale up or downsize of Power BI Embedded instances on demand. 

Now the question is how to do this correctly using ARM templates?

When I go into Azure Portal Power BI Embedded configuration blade and switch "Automation script" section in the script there is a property called "scale": null. But looks like this property just ignored.

What we figured out when we try to run deploy into existing resource(Power BI embedded) with different than current SKU name than actually, Power BI Embedded will start to scale up/down which is what we are trying to achieve. But the drawback is that the scripts end with an error, which is the undesirable outcome, as we can't distinguish the real error situation and if our scaling attempt was successful.

New-AzureRmResourceGroupDeployment : 18:34:47 - Resource Microsoft.PowerBIDedicated/capacities 'ndaxxxx' failed with message '{
  "error": {
    "code": "ResourceDeploymentFailure",
    "message": "The response for resource had empty or invalid content."
  }
}'
At line:12 char:2
+     New-AzureRmResourceGroupDeployment -TemplateParameterFile $powerB ...
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: ( [New-AzureRmResourceGroupDeployment], Exception
    + FullyQualifiedErrorId : Microsoft.Azure.Commands.ResourceManager.Cmdlets.Implementation.NewAzureResourceGroupDeploymentCmdlet
New-AzureRmResourceGroupDeployment : 18:34:47 - Template output evaluation skipped: at least one resource deployment operation failed. Please list deployment operations for details. Please se
e https://aka.ms/arm-debug for usage details.
At line:12 char:2
+     New-AzureRmResourceGroupDeployment -TemplateParameterFile $powerB ...
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: ( [New-AzureRmResourceGroupDeployment], Exception
    + FullyQualifiedErrorId : Microsoft.Azure.Commands.ResourceManager.Cmdlets.Implementation.NewAzureResourceGroupDeploymentCmdlet
New-AzureRmResourceGroupDeployment : 18:34:47 - Template output evaluation skipped: at least one resource deployment operation failed. Please list deployment operations for details. Please se
e https://aka.ms/arm-debug for usage details.
At line:12 char:2
+     New-AzureRmResourceGroupDeployment -TemplateParameterFile $powerB ...
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: ( [New-AzureRmResourceGroupDeployment], Exception
    + FullyQualifiedErrorId : Microsoft.Azure.Commands.ResourceManager.Cmdlets.Implementation.NewAzureResourceGroupDeploymentCmdlet
 =========================================================================================================
 DeploymentName          : Deploy_PowerBI
ResourceGroupName       : PowerBITest
ProvisioningState       : Failed
Timestamp               : 22.02.2018 16:34:25
Mode                    : Incremental
TemplateLink            : 
Parameters              : 
                          Name             Type                       Value     
                          ===============  =========================  ==========
                          env_name         String                     Dev       
                          powerbiinstanceName  String                     ndaxxxx
Outputs                 : 
DeploymentDebugLogLevel : 

Deployment PowerBI instance to Azure is finished

 
 ==============================================================================================================================
 #Deployment script
 
 
 $resourceGroupName = "PowerBITest"


#PowerBI Deployment 


    $powerBIParameterFilePath =  'C:\Temp\azure_templates\powerbi_parameters.json'
    $powerBITemplateFilePath =  'C:\Temp\azure_templates\powerbi_template.json'

	$newDeploymentName = "Deploy_PowerBI"
	Write-Host "Deploying Resources from Template - $powerBITemplateFilePath"
	New-AzureRmResourceGroupDeployment -TemplateParameterFile $powerBIParameterFilePath -TemplateFile $powerBITemplateFilePath -ResourceGroupName $resourceGroupName -Name $newDeploymentName
	Write-Host "Deployment PowerBI instance to Azure is finished"
 ##########