How to set the splunk_user in puppet-splunk module

[timeweaver]

The latest version of the puppet-splunk module has the following code for in the forwarder.pp file:

https://github.com/voxpupuli/puppet-splunk/blob/f93b0a9d33ea0f388597834bdf5b87fb0334a8b1/manifests/forwarder.pp#L174-L177

  String[1] $splunk_user                     = versioncmp($version, '9.1.0') ? {
    -1 => $splunk::params::splunk_user,
    default => 'splunkfwd',
  },

On our system, for versions of splunk forwarder greater than 9.1.0, this forces splunk_user to be splunkfwd regardless of what we set splunk::params::splunk_user to in hiera. Our systems have version 9.1.1 installed, but still have the splunk user set to splunk - since we've upgraded puppet is now trying to force this to change to splunkfwd - which of course fails since we do not have that user on our system.

How do we call this module with the splunk user of our choosing?
Any help appreciated.