Split Controller Architecture requires Controller role

The split controller architecture documented here:

https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/10/html/advanced_overcloud_customization/roles#Arch-Split_Controller

fails with the following error:

Could not find data item controller_node_ips in any Hiera data file and no default supplied at /etc/puppet/modules/tripleo/manifests/haproxy.pp

It looks like this is because the role is hardcoded in overcloud.j2.yaml ?

      controller_ips: {get_attr: [Controller, ip_address]}
      controller_names: {get_attr: [Controller, hostname]}

I can therefore workaround this by changing ControllerPcmk to Controller and editing the Controller role. I then add one ControllerSystemd custom role.

My guess is that this is coincidentally fixed by:

Change-Id: I36df7fa86c2ff40026d59f02248af529a4a81861

or maybe over-riding hieradata is required?

If the latter, perhaps a documentation update?