Azurerm provider - virtual_hub_connection - how to propagate to "None" route table?

I’m connecting internal (non-customer-facing) spoke VNets to a virtual hub - I’d like the connections to associate to their own route table (which I have, that’s all good), but to propagate to the “None” route table. This is supported in the portal, but the support for it in the azurerm provider is less than clear - the azurerm_virtual_hub resource surfaces the route table ID for the “Default” route table, but not the “None” table.

Do I do this with labels instead? As in,

resource "azurerm_virtual_hub_connection" "spokes" {
  for_each = local.spokes
  provider = azurerm.connectivity
  name                      = "spoke-${each.value.spoke_name}"
  virtual_hub_id            = var.virtual_hub_id
  remote_virtual_network_id = azurerm_virtual_network.spokes[each.key].id
  internet_security_enabled = true
  routing {
    associated_route_table_id = var.hub_route_table_ids[each.value.spoke_route_table]
    propagated_route_table {
      labels = [ "none" ]
      route_table_ids = [ ]

So, I’ve half answered my question - using the Terraform fragment above, I can get the spokes to show that they are propagating to the “none” label, and no longer appearing in Default, but I would expect to see something populating in the None route table. Or shouldn’t I?