Istio Operator - k8s advanced overlay add volume

Looking at using the Advanced Overlay capability to augment the installation of Istio.

The example show how to modify an existing element, but in my case looking to add an additional volume.

apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
name: primary
namespace: istio-system
spec:
profile: default
values:
global:
meshID: application
multiCluster:
clusterName: dev
network: shared
components:
pilot:
k8s:
overlays:
- kind: Deployment
name: istiod
patches:
- path: spec.template.spec.initContainers
value:
- name: init
image: someInit
- kind: Deployment
name: istiod
patches:
- path: spec.template.spec.volumes.
value:
- emptyDir: {}
ingressGateways:
- enabled: false
name: istio-ingressgateway

The selector (from what I can tell in the documents) requires a key:value to identity the path. Is there a way to add a new element to the list?