KubernetesDeployMode is not configurable at the GatewayClass/Proxy level

I tried to set this option

https://github.com/envoyproxy/gateway/blob/3052ea447e7b720f95d3e1a13ad16af8f037ffe3/api/v1alpha1/envoygateway_types.go#L319C10-L319C30

On my EnvoyProxy resource and it seems like it's not possible to accomplish this.

Asking around it seems like it's only available if I modify the default envoy gateway system config maps.

I don't really want that type of installation workflow.

I was hoping that I could

1. Install envoy gateway using kubectl
2. Configure this option using a special GatewayClass/EnvoyProxy combination

I know there are knobs using helm but I don't want to use Helm. I also don't want to carry a 'patch' because it's not a simple patch this field in a config map. You're actually patching a config inside of a yaml string.

eg.
https://github.com/envoyproxy/gateway/blob/3052ea447e7b720f95d3e1a13ad16af8f037ffe3/test/helm/gateway-helm/default-config.out.yaml#L38