In the OpenStack Nova API documentation for server creates, you can provide a hypervisor_hostname (with microversion >2.74) in the POST body.

https://docs.openstack.org/api-ref/compute/?expanded=list-hypervisors-detail,create-server-detail#create-server

I cannot find this supported in gophercloud anywhere. I attempted to use the existing scheduler hints, but this solution did not work. Is this field planned on being supported?

I believe the OpenStack python client supports this here:
https://github.com/openstack/python-openstackclient/blob/f1cb66a476b948093986afd18a00941b7807a9c4/openstackclient/compute/v2/server.py#L1685-L1694