Current endpoint override logic allows to specify only static URLs. There should be a way to specify a new alias by a new service name. E.g.

provider "openstack" {

  endpoint_overrides = {
    "network"  = "network-beta"
    "volumev2" = "volumev3"
  }

}

This logic was already implemented in gophercloud/utils#229 we need just to bump deps and adjust the docs.