Support proxyVmSize in Azure VM Image Builder service DevOps task

By default the proxyVmSize is Standard_a1_v2. This SKU is unavailable in the west europe region. Therefore the Azure VM Image Builder task is unusable in the west europe region when the subnet property is specified (existing network). The proxyVmSize property in the image template allows to set the SKU for the proxy vm to Standard_Fs2_v2 which is available in the west europe region.

Would it be possible to create a proxyVmSize property in the Azure VM Image Builder task and propagate that value to the Azure VM Image Builder image template?

https://learn.microsoft.com/en-us/azure/templates/microsoft.virtualmachineimages/imagetemplates?pivots=deployment-language-arm-template

https://learn.microsoft.com/en-us/azure/virtual-machines/linux/image-builder-networking#why-deploy-a-proxy-vm