Is your feature request related to a problem? Please describe.
I am currently trying to deploy external-secrets with FluxCD and the corresponding helmrelease custom resource. However, I have the problem that I have to deploy the ClusterSecretStore custom resource in addition to the helm chart.

I have already read your documentation GitOps using FluxCD (v2) in which the problem of the independently resource management between kustomization and helmrelease custom resources is explained. The solution described therein could solve my problem, but this would be problematic because the CRDs are currently deployed via the helm chart. That's why i was looking for a simpler solution.

Describe the solution you'd like
My suggestion is that additional manifests can be defined in values.yaml. This way they are part of the helm chart and helm takes care of the installation order.

Example:

values.yaml

# array of extraManifests
extraManifests:
- apiVersion: external-secrets.io/v1beta1
  kind: ClusterSecretStore
  metadata:
    name: vault-backend
  spec:
    provider:
      vault:
        server: "https://my-vault-server.com"
        namespace: "vault-namespace"
        ...

templates/extra-manifests.yaml

{{ range .Values.extraManifests }}
---
{{ tpl (toYaml .) $ }}
{{ end }}

I have also found this approach in other helm charts such as grafana.

To be honest it feels a bit strange to define manifests in the values.yaml, but it is a good way to solve my problem quite easily.

Describe alternatives you've considered
An alternative approach is already described in your GitOps using FluxCD (v2) documentation.