Modifiable Alias missing for Microsoft.Compute/virtualMachines/extensions

Hello,
I am trying to deploy configurations on VirtualMachine Extensions via Azure Policies, but I am missing aliases to deploy the updates.

In detail, I need to update the policy I try to deploy looks like the following:

`{
"properties": {
"displayName": "Enable AzureMonitor Extension AutoUpgrade",
"mode": "Indexed",
"description": "This policy enables the automatic upgrade of Azure Monitor Extensions.",
"metadata": {
"category": "Monitoring"
},
"parameters": {
"effect": {
"type": "string",
"metadata": {
"displayName": "Effect",
"description": "Enable or disable the execution of the policy."
},
"allowedValues": ["Modify", "Disabled"],
"defaultValue": "Modify"
}
},
"policyRule": {
"if": {
"allOf": [
{
"field": "Microsoft.Compute/virtualMachines/extensions/type",
"equals": "AzureMonitorWindowsAgent"
},
{
"field": "Microsoft.Compute/virtualMachines/extensions/publisher",
"equals": "Microsoft.Azure.Monitor"
},
{
"field": "Microsoft.Compute/virtualMachines/extensions/provisioningState",
"equals": "Succeeded"
},
{
"field": "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade",
"equals": false
}
]
},
"then": {
"effect": "[parameters('effect')]",
"details": {
"conflictEffect": "audit",
"roleDefinitionIds": [
"/providers/microsoft.authorization/roleDefinitions/9980e02c-c2be-4d73-94e8-173b1dc7cf3c"
],
"operations": [
{
"condition": "[greaterOrEquals(requestContext().apiVersion, '2020-06-01')]",
"operation": "addOrReplace",
"field": "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade",
"value": true
}
]
}
}
}
}
}`

The used field "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade" is not available in the listing of modifiable aliases for Virtual Machines, the policy deployment therefore fails with the following error:

I found, this alias is available for VirtualMachineScaleSets:

Is there a reason this is missing for Virtual Machines?
Is there a timeline bringing making this alias available (and modifiable)?

Best Regards
Christoph

Start by reviewing the modifiable-alias listing for Microsoft.Compute/virtualMachines/extensions and compare it with the corresponding VirtualMachineScaleSets alias. Confirm whether enableAutomaticUpgrade is supported for the requested API versions; the issue is complete when the alias is available and the shown Azure Policy deployment succeeds.

Written by the indexing model from the issue text.