Description:

Describe the desired behavior, what scenario it enables and how it
would be used.

Allow for custom Service (https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.27/#servicespec-v1-core) objects to be provided in KubernetesServiceSpec (https://gateway.envoyproxy.io/latest/api/config_types.html#kubernetesservicespec) instead of only ServiceType.
The only aspect overridden by Envoy Gateway would need be the selector object in the Service.
Having the Service object exposed to configuration allows for all sorts of custom deployments .

Specifically, I am looking for a way to support allocateLoadBalancerNodePorts: false.
Likely others will also start to look into custom: loadBalancerClass or other options.

[optional Relevant Links:]

Any extra documentation required to understand the issue.

See: https://kubernetes.io/docs/concepts/services-networking/service/#load-balancer-nodeport-allocation